UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

A photometric study of the Seyfert galaxies NGC 1566 and NGC 1068 Monger, Patricia Aline 1980

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1980_A6_7 M66.pdf [ 5.55MB ]
Metadata
JSON: 831-1.0085593.json
JSON-LD: 831-1.0085593-ld.json
RDF/XML (Pretty): 831-1.0085593-rdf.xml
RDF/JSON: 831-1.0085593-rdf.json
Turtle: 831-1.0085593-turtle.txt
N-Triples: 831-1.0085593-rdf-ntriples.txt
Original Record: 831-1.0085593-source.json
Full Text
831-1.0085593-fulltext.txt
Citation
831-1.0085593.ris

Full Text

C • I  A PHOTOMETRIC STODY OF THE SEYPERT GALAXIES HGC 1566 AND 1068 by PATRICIA A L I N E MONGER B.A., W i c h i t a  State  U n i v e r s i t y , 1975  A THESIS SUBMITTED I N PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES ( D e p a r t m e n t o f G e o p h y s i c s and A s t r o n o m y )  Be a c c e p t t h i s t h e s i s a s c o n f o r m i n g to the reguired standard  The U n i v e r s i t y  of B r i t i s h  Columbia  M a r c h , 1980 ©  Patricia  Aline  M o n g e r , 1980  NGC  In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l  fulfilment  an advanced d e g r e e a t  of  the  Library  I further for  shall  the U n i v e r s i t y  make i t  agree that  extensive  s c h o l a r l y p u r p o s e s may be g r a n t e d  this  written  thesis for  It  nf  i s understood  f i n a n c i a l gain shall  GBOPMSICS  AMO  D a t e MftZCH  /7,  /?&  that  not  Asr/tOAJcwy  The U n i v e r s i t y o f B r i t i s h C o l u m b i a 2075 W e s b r o o k P l a c e V a n c o u v e r , Canada V6T 1W5  I agree  r e f e r e n c e and copying of  this  copying or  for  that  study. thesis  by t h e Head o f my D e p a r t m e n t  permission.  Department  the requirements  B r i t i s h Columbia,  available for  permission for  by h i s r e p r e s e n t a t i v e s . of  freely  of  or  publication  be a l l o w e d w i t h o u t  my  ii  Abstract  Two visual NGC  dimensional and  1068  has  luminosity region  red  p h o t o m e t r y o f NGC  w a v e l e n g t h s has also  been  NGC  from  1566  the data  f o r e a c h component a r e  w h i c h show  the  outer  An  derived  the  shows t h a t the  inner  point  an e x p o n e n t i a l  edge t h a n a t t h e  that  the  c e n t e r The  i s also  aperture.  s h o w i n g an e n h a n c e m e n t o f r e d the  o u t e r edges of the For  NGC  determined  1068, for  feature  is  obscuration  by  color gradient the  outer  red l i g h t component.  dust.  emission  profiles  r<11".  not  c o l o r map  of  i n the  is  the  total  presented,  center  and  at  image.  the  bulge r e v e a l s a point  A  disk  point source  light  8^5  source  disk. Colors  5%  an  at  H°< i m a g e o f  c o m p o n e n t i s q u i t e weak, c o n t r i b u t i n g o n l y in  1566  of  c o n s i s t s of a nuclear and  at  NGC  Decomposition  component, a s p h e r o i d a l b u l g e ,  redder  and  baea o b t a i n e d .  obtained.  p r o f i l e s derived  (r<18") o f  1068  p e r m i t a b u l g e component t o  Subtraction  of  the  s o u r c e component i n t h e  observed The  in  c o l o r map  i n that the  the  seeing  f o r NGC  central region  convolved  r e d image..  visual 1068  be  image,  This  due  shows a  i s much r e d d e r  to  strong than  r e g i o n , f o r r < 1 8 " . T h e r e i s a l s o an enhancement i n along  the  m a j o r a x i s t h a t may  describe  a  bar-like  i i i  T a b l e Of C o n t e n t s  C h a p t e r 1. I n t r o d u c t i o n ................................... 1 1.  Some Observational Properties Of Seyfert G a l a x i e s .........................................1  2.  Observations  3.  O u t l i n e Of The T h e s i s  C h a p t e r 2.  4 .......3  1566  ..,.10  1.  Introduction  10  2.  Photometric  3.  Luminosity  3.  Discussion  C h a p t e r 3. 1.  NGC  And D a t a R e d u c t i o n s  NGC  Profiles  .......................... 12 ..................18 ..46  1068  ,  •--52  I n t r o d u c t i o n ......................................52  2.  Photometric  3.  Luminosity  3.  Discussion  C h a p t e r 3. Bibliography Appendix  Calibration  Calibration  ..74  P r o f i l e s ..............................33  Conclusions  ......105 ,,.109 111 .......119  iv  List  Of T a b l e s  T a b l e 1. D e t e c t o r C h a r a c t e r i s t i c s  ......................... 5  T a b l e 2. O b s e r v a t i o n a l E l e m e n t s Of NGC T a b l e 3. T a b l e 3. T a b l e 5. T a b l e 6.  1566  P h o t o m e t r i c C a l i b r a t i o n Of The V NGC 1566 ,. , , Photometric NGC 1566  Calibration  Surface Brightness Image Of NGC 1566 Surface  Brightness  Image Of NGC  Of  Image  14  Of  The  ... 16  R ....31  Distribution  Of  1566  The V ,  ,.40  1566  T a b l e 8. O b s e r v a t i o n a l E l e m e n t s O f NGC  #.51 1068  T a b l e 9.  P h o t o m e t r i c C a l i b r a t i o n Of The V NGC 1068 T a b l e 10. S u r f a c e Brightness Distribution Image Of NGC 1068 11. S u r f a c e B r i g h t n e s s Image Of NGC 1068  Of  The B Image Of .  Distribution  T a b l e 7. M o d e l P a r a m e t e r s F o r NGC  Table  12  Distribution ,  74 Image Of Of  Of .......78 The R 93  The  V .,.98  V  L i s t Of F i g u r e s  Fig.  1.  C o l o r - A p e r t u r e d e l a t i o n s F o r NGC  1566  ... 19  Fig.  2.  NGC  1566: V - r C o l o r Hap  Fig.  3.  NGC  1566 Red Image: I s o p h o t a l C o n t o u r s  ,...29  Fig.  4.  NGC  1566 Red Image: L u m i n o s i t y  ,..30  F i g . 5.  NGC  1566 Red Image: I n i t i a l  Fig.  6.  NGC  1566 Red Image: F i n a l D i s k  Fig.  7.  NGC  1566 Red Image: F i n a l B u l g e M o d e l s  Fig.  8.  NGC  1566 Red Image: R a s i d u a l N u c l e u s  Fig.  9.  NGC  1666 Red Image: R e s i d u a l s  Fig.  10. P r o f i l e s F o r I Zw  Fig.  11. NGC  1566 V i s u a l Image: I s o p h o t a l C o n t o u r s ........38  Fig.  12. NGC  1566 V Image: L u m i n o s i t y  Fig.  13. NGC  1566 V Image: I n i t i a l  Fig.  14. NGC  1566 V Image: F i n a l D i s k  Fig.  15, NGC  1566 V Image: F i n a l  Fig.  16. NGC  1566 V I m a g e : R e s i d u a l N u c l e u s  Fig.  17. NGC  1566 V Image: R e s i d u a l s  Fig.  18. NGC  1566 O b s e r v e d - C o n v o l v e d  Fig.  1 9 . NGC  1068: M a g n i t u d e - A p e r t u r e R e l a t i o n  Fig.  20. NGC  1068: C o l o r - A p e r t u r e  Fig.  2 1 . NGC  1 0 6 8 : V - r C o l o r Map  Fig.  2 2 . NGC  1068 Red Image: I s o p h o t a l C o n t o u r s  Fig.  23. NGC  1068 Red Image: L u m i n o s i t y  20  Profile  Bulge Model  32  flodel  .....33 ,34 ...35 35  21 From Kormendy  (1977)  37  P r o f i l e ............. 39  Bulge Model  ,..41  Model  ,,.42  Bulge Models  ,.43 44 ...45  Bulge R e s i d u a l s  ,.80  Relations  ...81 •  Profiles  ......51  ...91 .92  ..,....,..94  vi  Fig.  24. NGC  1068 Red-H* Image: L u m i n o s i t y P r o f i l e  95  Fig.  25. NGC  1068 R e d - f K Image: R e s i d u a l N u c l e u s  Fig.  26. NGC  1068 V i s u a l . Image: I s o p h o t a l C o n t o u r s  Fig.  2 7 . NGC. 1068 ¥ Image: I n n e r R e g i o n s  Fig.  28. NGC  1063 V Image: L u m i n o s i t y P r o f i l e s  Fig.  29. NGC  1068 V Image: B u l g e H o d e l s  Fig.  30. NGC  1068 V Image: R e s i d u a l s  Fig.  3 1 . NGC  1069 IK Image: C o m t a l P i c t u r e  Fig.  32. NGC  1068 H°< I m a g e : I s o p h o t a l C o n t o u r s  Fig.  33. NGC  1068 O b s e r v e d - C o n v o l v e d  Fig.  34. NGC 1068 V: L u m i n o s i t y P r o f i l e s From A p e r t u r e Photometry ., -.  .....96 97 ...99 .......100  ( n u c l e a r Begion)  Bulge R e s i d u a l s  .101 .....10 2 ..,,.103 ..104 ...,,.107 122  vii  A c k n o w l e d g e ments  I for  would l i k e  t o t h a n k my  suggesting the  me,  and  thesis advisor.  t h e s i s t o p i c , making t h e  Dr.  I am  most  appreciative  of  Fablman,  data a v a i l a b l e  e s p e c i a l l y f o r very p a t i e n t l y guiding  analysis.  G.  his  me  to  through  the  encouragement  and  w i l l i n g n e s s t o p r o v i d e a d v i c e whenever I a s k e d f o r i t . Dr.  Chris  observations, most o f my  the  Pritchet  d i d the  data reduction  Pritchet  a n a l y s i s and guite  for set  on  the  Alfonso  data reduction,  the  the  detector.  took  and  I am  t i m e t o h e l p me  right track  when  I  the  provided answering  grateful  with  the  found  to  data  myself  confused. S t e p h e n s o n Yang p r o v i d e d a good d e a l  the  Condal  software, i n addition to  d a t a and  taking  me  Dr.  preliminary  q u e s t i o n s about the  Dr.  and  U.B.C  programs  c o m p u t e r s y s t e m , as he  had  written.  Drs.  G l a l k e r , P.  like  t o t h a n k t h e m , and  itself  f r o m Dr.  6.  w e l l as  of  sharing  I also received  H i c k s o n , and  J . Auman,  useful c r i t i c a l  P u d r i t z , t o whom I am  information  about  some v e r y  useful  h e l p f u l advice for  which  comments on also  from  I  would  the  thesis  most g r a t e f u l .  1  Chapter  J  Introduction  Ji  Some O b s e r v a t i o n a l Since  the  distinct studies  of  surveys the a  type  Seyfert  on  (A.J.,v.73,pp discussion  accumulated t o  The its  two  (~1000 km/s)  are  infrared  i s not  not  as  continuum and  spiral  the  1968  results  comprehensive  (1977) r e v i e w e d t h e  and  the  of  known  a Seyfert the  data  Seyfert  galaxies  Most  that  those or  galaxy  presence of  spectrum.  distant  p o s s i b l e , but  r a d i a t i o n of  ultraviolet  absorption-line  and  sufficiently  and  of  time).  nucleus, in  as  occurrence  first  which d e f i n e  emission l i n e s  well  i t s n a t u r e . In  table  a  that  are  broad  of  the  morphological are  barred  nearby  are  spirals,  of  shows b o t h  an  subtypes.  The  is  at t h a t  star-like  classified  various  88,  a  as  of  held,  the  objects..Weedman presenting  of  was  as  have been many  type,  freguency  presented  galaxies  there  Seyfert the  Galaxies  Seyfert  1943)  galaxies  characteristics  classification all  1976,  (a t o t a l  prominant  Seyferts  these  of  understanding  Seyfert  836-916)  of  cf  determining  phenomenon, and  conference  Seyfert  (Seyfert,  galaxies  at  Of  identification  cf object  specific  aimed  galaxies  first  Properties  spectrum  seen, because  emission  lines  Seyfert  excess.  In  p r o d u c e d by  i t i s obscured  p r o d u c e d i n the  galaxies  by  most  cases,  the  the  s t a r s i n the  the  continuum r a d i a t i o n  central  regions.  galaxy  Seyferts  2  are nor  not  in  general  strong  do t h e y a p p e a r b r i g h t  Weedman (1971) d i v i d e d on  the  width  of  radio  sources,  a l t h o u g h some a r e ,  i n t h e X-ray region.  Seyferts  Khachikian  and  1 and 2 ,  i n t o two t y p e s ,  based  t h e B a l m e r l i n e s compared t o t h e f o r b i d d e n  l i n e s . F o r type  1 S e y f e r t s , t h e Balmer l i n e s a r e broad but t h e  forbidden  a r e n a r r o w e r , whereas i n t y p e 2 S e y f e r t s ,  Balmer is  lines  lines  and f o r b i d d e n  most e a s i l y e x p l a i n e d  emission region  lines  in  a r e o f t h e same w i d t h .  by t h e h y p o t h e s i s  Seyfert  than t h e Balmer l i n e s .  ( N e u g e b a u e r , e t a l , 1976) t h a t in  lines  1  that the  galaxies arise i n a different  T h e r e i s some e v i d e n c e  as  well  t h e two t y p e s o f S e y f e r t s . d i f f e r  the nature of the observed i n f r a r e d r a d i a t i o n . For Seyfert  in the nucleus, uv  whereas i n S e y f e r t  necessarily  guestioned t h i s  small  This  sample  suggestion, of  source  2 galaxies, reradiation  p h o t o n s by d u s t i n t h e c e n t r a l r e g i o n  more l i k e l y e x p l a n a t i o n . a  This  forbidden  1 g a l a x i e s , t h i s i s t h o u g h t t o a r i s e from a s y n c h r o t r o n  the  the  a p p e a r s t o be a  h o w e v e r , i s b a s e d on  Seyferts.  Rieke  (1978)  p i c t u r e on t h e b a s i s o f h i s i n f r a r e d s u r v e y o f  53  S e y f e r t s . He n o t e d t h a t i n most c a s e s i t was i m p o s s i b l e  fit  a s i n g l e power l a w t o t h e c o n t i n u u m r a d i a t i o n o f a  galaxy, as  the  of e i t h e r type. detection  I n a d d i t i o n , he c i t e s  o f 10 m i c r o n s i l i c a t e  S e y f e r t s , and t h e f a c t t h a t f o r b o t h steeper  of  infrared  Seyfert  evidence,  of  Seyferts,  continuum i s c o r r e l a t e d with a l a r g e r  f o r 0-E, t o s u g g e s t t h a t d u s t r e r a d i a t i o n i s a l s o a source of the i n f r a r e d luminosity  of type  such  i n 3 type 1  features  types  to  1 Seyferts.  a  value  prominant  3  The  nature  of the n o n s t e l l a r r a d i a t i o n source i n S e y f e r t  g a l a x i e s i s unknown. The h y p o t h e s i s nonthermal  emission  variability  i n t h e continuum  ( e . g. L y u t y i ,  that  are  1977,  radiation  de  of  several  considered  explanations  of  with  to  the  by G i n z b u r g  connection  Vaucculeurs,  1973).  of  size  be  nature and  the  similar of  these  Ozernoy  work  to  less  QSO's.  objects  (1977).  presented  Of  the  correlated  occurrrence  of  a of  This  also  than  1  galaxies Possible  have  been  interest i n  here i s t h e g u e s t i o n o f  wbether a l l s p i r a l g a l a x i e s pass t h r o u g h a S e y f e r t whether  has  Seyferts  For these reasons, t h e n u c l e i of S e y f e r t  often  discussed  source  mechanism i s s u p p o r t e d by o b s e r v a t i o n s  i n d i c a t e s t h a t t h e source i s compact, light-year.  the  the  Seyfert  with s t r u c t u r a l or e v o l u t i o n a r y  stage,  or  phenomenon i s  processes that  only  some s p i r a l s e x h i b i t . I t i s u s e f u l t h e r e f o r e t o study view  to  comparing  them  with  Seyfert galaxies  normal s p i r a l g a l a x i e s .  spectroscopic.pecularities are evident, d e f i n e t h e c l a s s . As t o m o r p h o l o g i c a l n o t e d by v a r i o u s o b s e r v e r s therein)  i s that  structure surrounding s e e n i n NGC Adams  possible  to  study give  1977,  have  a  t h e d i s k . One e x a m p l e  used of  Their  since i t i s these  ( c f Weedman, Seyferts  a  that  d i f f e r e n c e s , one f e a t u r e  1068, i n the Hubble A t l a s (1977)  morphological  some  with  and  faint of  references outer  this  can  ring be  photograph.  large-scale  image t u b e p l a t e s f o r a  80  galaxies.  Seyfert  Hubble, t y p e s  f o r the  It  was  not  g a l a x i e s , but the  a  results  of the s u r v e y i n d i c a t e d t h a t S e y f e r t n u c l e i o c c u r e d i n  most t y p e s o f s p i r a l s and  barred s p i r a l s .  the  might  Seyfert  suggested  may  galaxies  be  clusters,  where e l l i p t i c a l s  also  indicated  a  galaxies.  surplus  of  more t h a n  elliptical,  r e f l e c t t h e f a c t t h a t no  rich  No  which  S e y f e r t s are  nuclei  in  in  survey peculiar  Adams c o n f i r m e d t h e o c c u r r e n c e o f e x t e r n a l r i n g s i n that  determined  occurrence  whether  the  freguency  i s g r e a t e r than i n normal  A more d e t a i l e d regions  Adams  a r e more common. The Seyfert  of  found  some S e y f e r t g a l a x i e s , a l t h o u g h he n o t e d  structure  10%  of  study of the  Seyfert  galaxies  of  cannot of  be such  galaxies. structure  might  morphological p e c u l i a r i t i e s e x i s t  i t  of  determine  as w e l l .  the  central  whether o t h e r  F o r t h e two S e y f e r t  galaxies studied i n this thesis, particular attention w i l l  be  paid to t h i s question.  2. O b s e r v a t i o n s And  The and  22,  Data  observations 1978,  telescope  at  at  the  Cerro  element  charge-coupled  the J e t  Propulsion  al,  1978,  A. C o n d a l .  been  Condal,  made on t h e n i g h t s o f J a n u a r y focus  of  The  d e t e c t o r employed  device  on  Laboratory,  extensively 1979,  was  a  1.5m by  Pasedena,  1979),  C.  400xU00  loan to the observatory California.  discussed elsewhere  Pritchet,  21  the  Tololo Inter-American Observatory,  and  has  were  Bitchey-Chretien  Pritchet  device  Seduction  by  This  (Fahlman e t  therefore  i t  will  5  suffice  to  present  characteristics features  of  here  (Table  a  1) and  brief to  summary o f t h e  point  the system t h a t a f f e c t the  some  important  observations  analysed  T a b l e Ji  here: Detector  Characteristics  Size  9x9  Format  400x400  Center-to-center  spacing  23  mm  3x10  Bead-out n o i s e  27  Operating  -100* C  Spectral  temperature range  s  e"  e"  4000A-11000A  Quantum e f f i c i e n c y  —709E a t 7000A,  Thickness (aj  pixels  m  S a t u r a t i o n charge  of  out  operating  H0%  at  5000A  10/* T h e r e were a number o f d e f e c t i v e p i x e l s  pixels  on  the  a r r a y , which l i m i t e d  and  columns  the u s e f u l s i z e o f  d e t e c t o r t o 200x200 p i x e l s . E v e n w i t h i n t h i s r e g i o n t h e r e dead c o l u m n s b u t from  the  of the  central  were made t o e n s u r e  r e g i o n s of the  that  galaxy f e l l  on  the  were light  "clean"  areas  detector  (b) frame,  The and  from the  resulting  o b s e r v a t i o n s c o n s i s t e d o f an o b j e c t f r a m e , a a  flat  field  f r a m e . The  o b j e c t frame t c e l i m i n a t e  background  for  efforts  the  light i m a g e was  and then  variations in pixel  the  dark  d i v i d e d by response.  s k y f r a m e was  the  the  subtracted  contribution  current flat  to  of  the image.  field  sky  to  the The  account  6  (c) red  The  CCD  and n e a r  included used  has a r e l a t i v e l y  infrared  to  wavelengths,  so  that  a  filter  s u p p r e s s r e d l e a k s . Thus t h e f i l t e r  were n o t t h e s t a n d a r d J o h n s o n  very  h i g h guantum e f f i c i e n c y  similar  bandwidth  and  at was  combinations  V and  B filters,  effective  wavelength  b u t had  a  (Pritchet,  1979) . (d) The  r e a d - o u t n o i s e o f t h e CCD  instrumental the  -vTT  unit.  flucticn  distribution  for  the  photon  the  ratio  the  and  a  2  exposure,  a  1  and a 20 s e c o n d diodes  flux,  photons. is  about  At  a  Poisson  half-saturation Typically  the outer  i m a g e s were a t a b o u t 30 i n s t r u m e n t a l  units,  ^20.  1566,  minute 1068,  400.  assuming  the  i m a g e s o f NGC  o b t a i n e d . F o r NGC  the  by  a signal-to-noise ratio  filter,  of  Thus t h e n o i s e i n t h e d a t a i s d o m i n a t e d  for  of  Two  the  1  in  signal-to-noise contours  c o r r e s p o n d s t o about  a 2 minute exposure exposure  using  the  using the B f i l t e r ,  f o u r i m a g e s were t a k e n , a 2  V  were  minute  V  m i n u t e e x p o s u r e i n H°<, a 1 m i n u t e R e x p o s u r e , E e x p o s u r e . The  1 minute  E exposure  saturated  a t t h e c e n t e r o f t h e i m a g e , so t h e c e n t r a l  region  t h e 20 s e c o n d e x p o s u r e , a p p r o p r i a t e l y s c a l e d t o a c c o u n t f o r different  exposure  , and t h e r e s u l t i n g  The written  e x p o s u r e t i m e s , was  data  reduction  primarily  written reduction  by  A.  by  C.  Condal  included  combined w i t h t h e  done  Pritchet,  removing  minute  c o m p o s i t e image was a n a l y z e d . .  was  and  1  using a s o f t w a r e package together  t h e a u t h o r . The the  dark  with  routines  preliminary  current  and  data sky  7  background,  dividing  by  the  flat  field,  and  d e f e c t i v e columns of p i x e l s with t h e i n t e r p o l a t e d surrounding  columns.  columns occured center  replacing  mean o f  the  T h i s was p o s s i b l e b e c a u s e t h e d e f e c t i v e  i n r e g i o n s o f t h e image f a r e n o u g h  that the luminosity p r o f i l e  changed o n l y  from  the  slightly  from  column t o column. The frcm  orientation  and s c a l e s i z e o f t h e d e v i c e was o b t a i n e d  o b s e r v a t i o n s o f t h e T r a p e z i u m i n O r i o n . From t h i s a s c a l e  s i z e o f .415 a r c s e c / p i x e l was Two methods o f d i s p l a y i n g Using  a modified  University egual  of  intensity  calculates  determined. t h e i m a g e s have been u s e d  v e r s i o n o f a p r o g r a m made  were p l o t t e d f o r e a c h i m a g e . The p r o g r a m  an e f f e c t i v e r a d i u s f o r e a c h c o n t o u r ,  luminosity profiles A  second  gualitative  by t h e  method  remote  discussed  California),  which  in  detail  by  In  of B r i t i s h  applications. by  commands  a  this  strictly  t h e use o f  (Comtal  Condal  entered  C o l u m b i a a n d made This  system  e t a l , (1979). television on  Sensing  available has  been  B r i e f l y , the  screen  an a t t a c h e d  the  Corporation,  i s owned by t h e Remote  i m a g e s a r e d i s p l a y e d on a c o l o r controlled  contour.  p i c t u r e o f t h e i m a g e s , was t h r o u g h  sensing  also  d e f i n e d by r  of d i s p l a y , which presented  Group a t t h e U n i v e r s i t y for  the  were d e r i v e d .  CCMTAL V i s i o n One Image P r o c e s s i n g System Pasadena,  by  B r i t i s h Columbia Computing C e n t e r , c o n t o u r s o f  ={A/ff, where A i s t h e a r e a e n c l o s e d way  available  here.  which keyboard.  number o f o p e r a t i o n s c a n be p e r f o r m e d on t h e i m a g e s .  i s A  For the  8  display  presented  intensity picture system  of  how  proved  display  presented  NGC  type  1,  Of  two  so  distance  for  structure Chapter section  published  of  1068  2 will  discuss  reviews tbe  The  second  of the  the  illustrated  on  of  central  wavelengths.  of  image,  as  in this  image  where by  t h e s i s are  2 Seyfert  t h e s e two  S e y f e r t s . They a r e  galaxy,  results  This where  each  chapters,  i s a type  the  the  images,  and  the these  galaxies  CCD  analysis  NGC  1068 is  i s useful  in  ascribed  at a p p r o x i m a t e l y the  a n a l y s i s and  to  same  comparison  of  regions. the  observations  observational at  section  profiles. of  the  NGC  with the  and the  the  and  The  radio  photometric  third  final  luminosity  1566.  t h a t have been  infrared,  deals  In  of  studies  optical,  observations,  luminosity  NGC 1566  different physical conditions  this  discusses  V-E  image.  subseguent  reported  on  calibration  the  COMTAL d i s p l a y s o f  which f a c i l i t a t e s  of  gualitative  analyzed.  comparison  us,  a  the  Thesis  of the  types  the  be  NGC  that  present  and  to i n t e r p r e t .  the  each  galaxies  1566.  two  first  of  The  consideration  the  in  systems, w i l l  2s. O u t l i n e  and  p l o t s and  features  to  i n d i s p l a y i n g the  is difficult  be  The  images were m a g n i f i e d ,  i n t e n s i t y changed a c r o s s  most u s e f u l  contour  display  the  the  The  salient  the  l e v e l s were c o l o r - c o d e d  a contour  will  here,  section  section, profiles  the are  9  considered,  and  the derived s t r u c t u r a l components are compared  with those of normal s p i r a l  galaxies.  E x a c t l y the same o u t l i n e i s f o l l o w e d discussion studied  NGC  1068,  This  at a l l wavelengths, and  previous The  of  observational  galaxy  profiles  Appendix has  photometric  work  on  in  section  3,  been NGC  in  and  photometry.  in section  section  2,  1, the  the comparison with  included  in  1068  further  is  the  4.  p a r t i c u l a r emphasis on the d e r i v a t i o n of from the  been e x t e n s i v e l y  i n v e s t i g a t i o n s i s given  normal s p i r a l s i s presented i n s e c t i o n An  has  the  a comprehensive review of  photometric c a l i b r a t i o n i s discussed  luminosity  i n Chapter 3 f o r  which  the  previous  discussed,  luminosity  with  profiles  10  Chapter 2  NGC  J.  J566  introductiop  This  galaxy  was  classified  Vaucouleurs and de vaucouleurs presence  as  (1961)  a S e y f e r t galaxy by de on  the  basis  of  the  of wide emission l i n e s of BX, H$, [b III] /\5007, and  weak ~ j 0 I i ] )\3727. Few s p e c t r o s c o p i c  or  photometric  studies  have been made of t h i s o b j e c t , d e s p i t e the f a c t t h a t i t i s one of  the  brightest  declination  1566,  Gerola h/S  because  of  its  southerly  (-55 ). p  Shobbrook NGC  Seyferts,  (1966a) observed the n u c l e a r e m i s s i o n l i n e s  and  measured  (1970) reported  decreased  and  the  radial velocity.  P a s t o r i z a and  changes i n the emission spectrum,  the [0 III] l i n e s enhanced r e l a t i v e  s p e c t r a of Shobbrook and (1972) f u r t h e r described  the  de  Vaucouleurs.  Smith  a type  1 S e y f e r t , t h a t i s , one with narrow f o r b i d d e n  and  broad  Balmer  spectrum more e x t e n s i v e l y emission  lines,  Osmer  et  al  the  (1974)  and reported  measured  to the et  (1974)  al 1566  lines  studied  the  and measured i n t e n s i t i e s f o r s e v e r a l an asymmetry  as well as measuring the continuum between Martin  with  the spectrum, and c l a s s i f i e d NGC  as  lines.  in  intensities  i n the Hy? p r o f i l e , 3390A  and  7100i.  of the e m i s s i o n l i n e s i n  wavelength r e g i o n 3300& to 6750A, and again  reported  and  11  apparent values  variation of  P a s t o r i z a and  to determin the  B/] and  i n the  i f the  Gerola, although  variation  c o n t i n u u m . As  [0 I I I ] l i n e s c o m p a r e d t o  was  i n the l i n e s  b e c a u s e of t h e b r o a d  Infrared (1973),  who  observations  listed  indicated  that  al  a t 408  the  De  B r u y n and  Wright  Cameron and  Shobbrook (1973),  Wright,  wbo  also  - The that  aperture  who  also  i t  by  Smith  but  made no  the  MHz  Smith  et  al  presented  et  al  exhibits  al,  only  in  that  et the  30  0400-59.  f l u x by  assuming  measured  by  observations.  (1972), isophote  data.  weak  and  Cameron  Quintana  suggest  freguencies  This  the photometry of Quintana  lines et  sizes  and  X-ray source  (1976) d e r i v e d a 1415 between  Glass  t o be c o n c e n t r a t e d  Seyfert  by  and  de  Vaucouleurs  maps  and  reported a  result et a l  g e n e r a l c o n s e n s u s among t h e o b s e r v e r s  emission (Osmer  were made by  i n tbe n u c l e a r B magnitude, from comparison w i t h  S h o b b r o o k and confirmed  GHz,  the  p h o t o m e t r y f o r t h i s g a l a x y has b e e n p u b l i s h e d  (1966b),  variation  1566  (1974) a t 2700 MHz,  22.2  spectrum  Optical  NGC  associated with the  Wilson  a power l a w  of  for  o b s e r v a t i o n s h a v e b e e n r e p o r t e d by  MHz,  c o u l d be  or  wings.  IE r a d i a t i o n tends  (1975) a t 20 and  nucleus  themselves,  intensities  JHKL p h o t o m e t r y f o r 3  the nucleus. Eadio (1971)  not p o s s i b l e  p o i n t e d o u t by Osmer e t a l , i t i s d i f f i c u l t  t o p l a c e the continuum i n measuring l i n e Balmer l i n e s  i t was  the  was  the  further  (1975). o f NGC  1566  characteristics.  is The  a r e f a i n t compared t o those o f o t h e r S e y f e r t s 1974)  as  is  the  nuclear  magnitude  (de  12  Vaucouleurs,  1973).  indicate that this excess  as  has  The i n f r a r e d  g a l a x y does been  observations of Glass  not  detected  in  ( e . g. B i e k e and Low, 1 9 7 2 , K l e i n m a n n Table  2 ( a f t e r de V a u c o u l e u r s ,  f e a t u r e s o f NGC (1S56), S e r s i c and  1566. P h o t o g r a p h s (1957), Shobbrook  de V a u c o u l e u r s  have  a  other  strong  infrared  Seyfert  galaxies  and W r i g h t ,  have been p u b l i s h e d by E v a n s (1966a), Smith e t a l  Table 2  B.A. Dec 1,  Of NGC  1566  4^18:9  (1950)  -55°04'  (1950)  264',  b  -43°  L, B  235* , -41*  Type  SAB  Velocity  +1393  Apparent Color  magnitude  Mean a x i s Face-on  velocity  2. P h o t o m e t r i c  km/s  10.4  0.85  ratio  diameter  Corrected  (s) be  0.77  (B-V)  Calibration  1974)-.  1973) s u m m a r i z e s t h e b a s i c  (1973).  Elements  (1973)  6.'6 +1173  km/s  (1972),  13  B e c a u s e c f t h e e x p e r i m e n t a l n a t u r e o f t h e J P L CCD no  detailed  calibration  instrumental  unit  calibration  within  corresponding  to  with  by  the  the  a p e r t u r e s . The  this  V magnitudes.  i n terms  of  nuclear diameter de V a u c o u l e u r s  annuli  pixel  diameter of  the  simulated  Because o f  the  necessary  rather  measured f o r NGC  than 1566  (1968) i s 7i'0, t h e r e f o r e  completely contained i n the s m a l l e s t  the photometry  Table 3 l i s t s  of  diameters  comparing  per  photometric  boundary  aperture  and  published  the  flux  r e p o r t e d f o r t h i s g a l a x y , i t was  de V a u c o u l e u r s and  in  of  integrated  a c h i e v e d by summing t h e  circular  the photometry  t h e n u c l e u s was used  each  variability  calibrate  circular  to  a  the Therefore  p u b l i s h e d photometry,  photometry nuclear  exists.  f o r t h e V image was  intensities  existing  of  camera,  o f Smith e t a l (1972), which  the photometric c a l i b r a t i o n  aperture was  thus d e r i v e d .  8'i5.  14  Table Photometric  Ap.  Diam  V  CCD  13. 17  8^5  17'  The  annulus  v  V  galaxy a  13.36  -14.23  27.59  8."5-26"  12.62  -14.99  27. 61  SI'5-34"  12.16  -15.4  27. 56  V-v =27.587 +0.025  i s the  aperture mag. for  the  other  V aperture  photographic  for  aperture  diameter  The  28^8.  simulated  same a n n u l u s ,  mag  (standard mag/a^s*?  data  o f Shobbrook  diameter  15l'6  p h o t o m e t r y o f the l e a d i n g to a  photoelectric  photometry of Smith et a l . calibration  m a g n i t u d e has  varied  from  derived  upper  limit  subtracting  from  the  the  V-v  i t can  seen  t h a t determined to  observed  the  for  this  He  lists  V=11.85 mag is  for 12.96  d a t a g i v e s v=-14.68  value  calibration  be  (1966b).  magnitude  CCD  agreement  Prom t h i s  1  and  Then t h e a n n u l a r  with  error)  photometry p u b l i s h e d  satisfactory  an  V-v  v  -15.68  only  V=12.33  CCD  1566  8: 5-17"  = V +27.587-1. 88  The  NGC  -15.38  11.8 Mean  V Image Of  -(14.91  12. 11  34"  Of  -14.08  12.51  26 "  Calibration  3  of  27.64,  in  d e r i v e d from  the  that the by  nuclear  nuclear  V  S m i t h e t a l . They V  l u m i n o s i t y i n the  magnitude 81'5  by  diaphragm.  15  the  luminosity  brightness this  they  13.5.  egual  assuming  calibration  brightness in  18.94  mag/n'i  intensity  i s subtracted  from  aperture,  the r e s u l t i n g  nuclear  magnitude  observations magnitude scales of  of 1 year  this  varied  Smith  make  et  al  et  a l (1975) showed  as  much as a f u l l  The  irregularity  exists.  to  and  would  be  a background  this  background  .19  mag s i n c e t h e  showed t h a t t h e n u c l e a r  B  m a g n i t u d e on t i m e  of the o b s e r v a t i o n s  to  determine  i f any  exists. a  formal size  e r r o r o f .06 mag f o r t h e i r  i s not s u f f i c i e n t t o  that the n u c l e a r  calibration.  determine  i f  any  o f the f a c t while  that  of this  galaxy  periodicity  i f .variability  Quintana  one of  of  or l e s s . make  apertures i s  B  agree i n  discrepant,  the nucleus  i t  variation  v a r i a b i l i t y i n the  the outer  the inner  account  B magnitude h a s v a r i e d by  magnitude on t i m e s c a l e s o f 1 y e a r  o f the o b s e r v a t i o n s  expected  CCD  calculated f o r this  by  i n the photometric  CCD c a l i b r a t i o n ,  the  V m a g n i t u d e i s 13.69. T h u s t h e  I n c o n s i d e r a t i o n of t h e observed  magnitude, the  the i n t e n s i t y  for  to  If  The i r r e g u l a r i t y  list  the discrepancy  impossible  14.55.  diminished  p h o t o m e t r y . An e r r o r o f t h i s for  of  From  3, t h e b a c k g r o u n d  leads  i t impossible  of variation  surface  V magnitude o f  annulus  by a s much as a f u l l  or l e s s .  galaxy  periodicity  has  This  o f S m i t h e t a l . (1975)  has  i n Table  i n the corresponding  i n t h e 8i'5 a p e r t u r e  V  background  i n t h e 8^5-17" a n n u l u s .  given  magnitude  nuclear  a  an upper l i m i t t o t h e n u c l e a r  the  observations  by  t o t h a t observed  derived  From  surface  obtained  as  were t h e  16  source o f the d i s c r e p a n c y , then t h e best e x p l a n a t i o n calibration points  results  will  be  consideration  i s that  further  of  the  the  f o r the  nucleus has v a r i e d . These  discussed  in  photometric  Chapter  3,  calibration  in  of the  o b s e r v a t i o n s of NGC 1068. To date, there i s no published E photometry f o r NGC 1566. However, o b s e r v a t i o n s were  recently  made  at  Las  Campanas,  using a BCA 9658E tube, by C. HcAlary, who has k i n d l y made the data  available  the c a l i b r a t i o n owing  to  f o r c a l i b r a t i n g the CCD image. T h i s data, and o b t a i n e d , i s presented  the v a r i a b i l i t y  i n Table  4.  Again,  of the nucleus, the c a l i b r a t i o n was  done using a n n u l i with i n n e r diameter  9".  Table 4 Photometric Ap diam 9^0  E 12. 836  11.280  2225  29225  10.823  C a l i b r a t i o n Of The B Imaqe Of NGC 1566 CCD r  annulus  E  CCD r  E-r  -13.57  9"-22:5  11. 576  -14.30  25.874  9"-29.*25  11. 008  -14.80  25.811  -14.75  -15. 11  Mean E-r=25. 843 +.032 mag (standard e r r o r ) /^,= T+25.843-1.88  The  mag/atwc 1  outermost simulated aperture f o r the CCD V image  has  17  a  signal-to-noise  ±.05  mag.  For  60,  f o r an  from  listed  1b the  by  de  o f ±.02  Vaucouleurs  from  simulated  interest  v-r, the  f o r aperture center, the  size.  This  Seyfert  galaxies  regions.  In  observed, regions  data  in the  Stein  p h o t o m e t r y o f t h e CCD  >13".  In  an  ultraviolet colors  1566,  although  i n fact  being  i n the  and  attributable  t o a nonthermal continuum  w h i l e f o r S e y f e r t 2 g a l a x i e s such probably  due  to  as  most  central is  also  central in  the  paucity  of  "blue  blue  E-V  nuclei"  radiation  from  infrared.  (1976) c o n c l u d e infrared  termed  from  aperture  of t h i s  the  most o f t h e  larger  the  g u i t e t e n t a t i v e . I t i s the  observed  is  excess  o f NGC  g a l a x i e s , the  excess  a  the  in  1a  derived  fact that  in  indication  Seyfert nuclei  Weedman  Figure  decreasing  excess  that  w i t h i n 8"  i n view o f t h e  NGC  data. I t i s  show  addition,  infrared  regions i s emitted and  of  about  for  relation,  some  although  is  and  (1968).  is  suggestion  accuracy  (1972),  Vaucouleurs  i n b l u e r B-V  There  t h a t leads to  central  al  i n c r e a s e s with  an  relation  the l i t e r a t u r e ,  et  color-aperture  cases,  well.  makes t h i s  color  show  most  (B-V)-aperture  de  surprising  which r e s u l t s as  and  diameters  not  an  color-aperture relation  that the l a r g e r apertures  v-r c o l o r  is  giving  signal-to^-noise r a t i o  Smith  aperture  t o note  20,  mag.  photometry of  i n s t r u m e n t a l v-r  of  about  g i v e s t h e B-V  g i v e s the the  of  t h e B image, t h e  accuracy  Figure 1566,  ratio  t h a t f o r most S e y f e r t 1  ultraviolet source  NGC  thermal  1068,  excesses i n the the  reradiation  are  nucleus, infrared  by d u s t .  As  18  discussed  i n Chapter  guestion.  1,  Dust c l o u d s  V i s o p h o t a l contours asymmetry  this  suggestion  have been d e t e c t e d  presented  in  i n the inner regions,  and  clouds.  By c o n t r a s t , no asymmetry of  NGC  these  galaxies  that  the central,  that  o f NGC The  trend  be  regions  discussed  3  1068, and t h e  show  attributed  i s noted  in  the  2 and 21) i l l u s t r a t e  r e d , region  the  o f NGC  isophotal  this  as w e l l ,  1566 i s s y m m e t r i c ,  are red, regions  1566  (v-r)-aperture  also  in  while  again  illustrates  relation,  the intermediate  in  regions  i n c r e a s i n g l y red.  that the  are  This  the  bluer,  point  will  profiles,  Profiles  1566 i s c l a s s i f i e d  (s)  be.  In  offlinearly  described y C= L  dust  i n s e c t i o n 3.  Vaucouleurs  form  marked  t o the obscuring  general,  i n t h e de a  spiral  Vaucouleurs galaxy  with  r a d i u s , and  a  system  has  c o m p o n e n t s : a d i s k , i n which t h e l o g o f t h e s u r f a c e falls  a  f u r t h e r i n d i s c u s s i o n o f the l u m i n o s i t y  Luminosity  NGC  Chapter  to  ( s e c t i o n 3 ) . The COMTAL v - r images o f  (Figures  in  the outer  SAB  1566  i n NGC  open  1068 i s a s y m m e t r i c .  noted  presented  3.  be  v - r COMTAL image o f NGC  central and  may  still  which i s n o t o b s e r v e d i n t h e E  image,  contours  which  is  spheroidal  two  as main  brightness bulge.  De  (1948) f o u n d t h a t t h e s p h e r o i d a l component c a n be  by a s u r f a c e A+Br  i l  brightness-distance  where  M- i s  the  surface  relation  of the  brightness  in  19  /Q  i  .7  1  .g  1  .f  7^  1  1_  1-0  I-l  ^7  To  I  l-X  E^-l  1-3  I_  1-i  /.?  '<»  H  1-7  I*  1-1  <2<7  F i g u r e 1: (a) v - r c o l o r - a p e r t u r e r e l a t i o n o f NGC 1566, d e r i v e d from the s i m u l a t e d a p e r t u r e photometry of the CCD d a t a . A p e r t u r e diameter i s i n a r c s e c o n d s . (b) B-V c o l o r - a p e r t u r e r e l a t i o n . The p o i n t s are from the p u b l i s h e d photometry l i s t e d i n the t e x t , s e c t i o n 2.  F i g u r e 2: COMTAL p i c t u r e o f the c o l o r map o f NGC 1566. The r e d d e s t a r e a s are t h o s e w i t h l a r g e s t v - r , and the w h i t e a r e s a r e those w i t h smallest v - r .  21  mag/ ( a r c s e c ) . z  Kormendy component  in  (1977)  has  pointed  many  cases  brightness at large r a d i i .  out  contributes  that  the  spheroidal  significantly  T h e r e f o r e t h e two c o m p o n e n t s o f t h e  luminosity  profile  parameters  d e s c r i b i n g t h e d i s k and b u l g e  must be s e p a r a t e d i n o r d e r t o d e t e r m i n e t h e structure.  For the data presented h e r e , t h e decomposition in  an  iterative  Kormendy  to the  was  done  method, f o l l o w i n g t h e p r o c e d u r e o u t l i n e d  by  (1977):  (1) F i t t h e d a t a t o a d i s k p r o f i l e  at the outer r a d i i  (r  > 11") . (2)  Subtract  get a r e s i d u a l (3) bulge 1.35<  the  disk  profile  from t h e o b s e r v a t i o n s t o  bulge  F i t a de V a u c o u l e u r s b u l g e p r o f i l e  at  intermediate  radii  r' <1.55 f o r t h e v i s u a l /<,  (1.2< r ^ O . 4  (5)  a residual f i tt h i s  (6) i t e r a t e The  bulge  the  residual  f o r the r e d image,  image).  (4) S u b t r a c t t h e b u l g e p r o f i l e determine  to  from t h e  observations  to  disk.  r e s i d u a l d i s k t o a new d i s k  profile.  f r o m s t e p 2. was  fitted  to  a  de  Vaucouleurs  law  i n t e r m e d i a t e r a d i i because a t s m a l l r a d i i s e e i n g e f f e c t s  at must  be c o n s i d e r e d . I n t h i s r e g i o n s e e i n g e f f e c t s c a u s e t h e p r o f i l e to  deviate  iterative (observed)  from  procedure bulge  a  straight  l i n e l o g I-vs-r  i s used t o s e p a r a t e t h e from t h e d i s k .  relation.  seeing  The  convolved  I n t h e r e g i o n where t h e d i s k  22  model i s  fitted,  observed  deVaucouleurs  unconvolved  the  seeing  convolved  law,  although  bulge  follows  the  the parameters of the  bulge law w i l l d i f f e r s l i g h t l y from  the  observed  relation. The contour map Figure  3.  This  f o r the red image of NGC  map  d e s c r i b e d i n Chapter  was  produced  1. The image  running mean smoothing  1566 i s shown i n  using the contour r o u t i n e  was  smoothed  with  a  3x3  p r i o r to a n a l y s i s .  Table 5 g i v e s the s u r f a c e b r i g h t n e s s d i s t r i b u t i o n f o r the red  image,  initial  i s plotted in Figure a.  which  residual  procedure  was  bulge  stopped  profile. when  the  The  6  shows  iterative  parameters  f u n c t i o n s changed by l e s s than .01 i n Figure  F i g u r e 5 shows the  the f i n a l i t e r a t i o n  of the  successive  the  entire  fitting  disk p r o f i l e f o r the red  r e g i o n . The d i s k i s l e s s w e l l  In order t o examine the i n n e r r e g i o n of NGC  effects.  correct  the  the  final  The seeing p r o f i l e was  s t a r superimposed center,  can  be  bulge  determined,  region.  l  to  It  bulge p r o f i l e i s very w e l l determined over  but the f i t i s w i t h i n 2.57« over the f i t t i n g  necessary  fitting  iterations.  image, and F i g u r e 7 shows the f i n a l bulge p r o f i l e . seen t h a t the f i n a l  fitting  1566,  profile  for seeing  a  foreground  on the image c f the galaxy about  15" east of  which  can  be  determined from  i t is  seen e a s i l y on the Cordoba  p u b l i s h e d by de Vaucouleurs (1973, P l a t e 2).  The  was  i n t e n s i t y of the  corrected  to account f o r the background  star  plate image  galaxy, by s u b t r a c t i n g from the s t a r image the expected galaxy  23  brightness the  at t h a t d i s t a n c e from the c e n t e r ,  initial  plotted  i n Figure  profile  can  dashed-line part  luminosity  of  8.  be  seen  image  by  from  a  the  result  from  Figure  the  with  a 2-dimensional,  spherically  inner  9  necessary on  the  was  array  d a t a , s i n c e the by  determined  symmetric  then  The  convolving  the  bulge  model,  changes r a p i d l y  each  of  these  and  model  to  the  averaging  bulge the  final  r  law  bulge  distribution  r=0.  of the  This  the  a  intensity  over the  profile,  entire model the  until  the  p r o f i l e , after convolution.  The  were a d j u s t e d  f o u n d t h a t a b u l g e model w i t h  7._ surface  brightness  form -  convolution  interval  and  parameters final  was  array elements i n t o  model p r o f i l e i s shown i n F i g u r e was  near  For  i t  l u m i n o s i t y p r o f i l e of the convolved  model p r o f i l e f i t t e d  after  law  / t  subelements,  compared  unconvolved  It  of  The  bulge  symmetric s t a r image.  f o r each subelement from the  element.  convolved  r  dividing  100x100 a r r a y o f  was  elements  that  determined  t o account f o r the e f f e c t s of the sampling  done  array  spherically  The  contours.  m o d e l , d e t e r m i n e d f r o m t h e f i n a l b u l g e p r o f i l e , and it  3.  intensity.  t h e b u l g e p r o f i l e was  2-dimensional,  seeing  replacing  tbe expected galaxy  on  from  profile is  actual  of  g u i t e w e l l t o the t r u e  e f f e c t of seeing  generating  resulting  consideration  contours  with  corrected region f i t s The  The  That t h i s r e p r e s e n t s  p a r t of the  the  profile.  determined  /A 33?  with  +^  the  723  r* H  seeing  ,  (i)  disk,  f i t the  observed  24  profile (1)  as determined  from t h e i t e r a t i v e  procedure.  Equation  i s l o w e r i n s l o p e and i n t e r c e p t t h a n t h e s t r a i g h t l i n e o f  F i g u r e 7, b u t a f t e r c o n v o l u t i o n t h e f i t indicates  that  the  d i s t a n c e s of s e v e r a l The  affects  arcseconds  convolved  observations  seeing  bulge  f o r the  the  profile  then  image,  subtracted and  the  e x a m i n e d . F i g u r e 9 shows t h e r e s i d u a l p r o f i l e , of  a  disk-type  profile,  good.  and  a  star-like  determined  -t~. 03/?  nucleus.  even  the  residuals  were  which  consists  the  iteration  from  o f t h e form .  7r  This  nucleus  profile,  after  s u b t r a c t i n g t h e d i s k , i s p l o t t e d i n F i g u r e 8. I t c a n be to  a Gaussian  However,  intensity  seems  in  keeping  disk  with  profile  t h e way t h e o b s e r v e d attempt  the observed  fits  to  the  from  region.  This  weakness o f t h e S e y f e r t  s e n s e , and e x a m i n i n g  line  relation  p o i n t s o s c i l l a t e about t h e s t r a i g h t  determine  the  straight  to  T h e r e a p p e a r s t o be some r e g u l a r i t y i n line.  i f t h i s t r e n d was s i g n i f i c a n t  made, by s u b t r a c t i n g t h e c o n v o l v e d nucleus  circular  a b o u t 5% o f  o f NGC 1566.  w i t h i n 4X a t a l l r a d i i .  An  fitted  o f t h e form  i n s i d e a n 81'5 d i a m e t e r  characteristics The  distribution  the nucleus i s guite f a i n t , c o n t r i b u t i n g  the luminosity  at  from  procedure, with a surface brightness d i s t r i b u t i o n y ^ e = '7-  This  from t h e c e n t e r .  was  red  i s very  observations, the r e s u l t i n g  bulge in  and  the  disk.  No  full  the  was  star-like  2-dimensional  systematic  trend  25  was e v i d e n t f r o m so  small,  these  i t  i s n o t p o s s i b l e t o a s c r i b e any s i g n i f i c a n c e t o  oscillations. Figure  for  t h e d i s k c o n t o u r s , and s i n c e t h e d e v i a t i o n i s  the  18 shows t h e o b s e r v e d  bulge  minus  can  The u n d e r - l u m i n o u s  these  radii  the  disk  conclusions are also affected of  this It  is  of  visual  (7"<r<10 ) M  significant,  component  image,  although  dominates,  by e r r o r s i n  the  so  the  determination  i n t e r e s t t o compare t h e r e s u l t s o b t a i n e d  o f Kormendy using  decomposition  the  (1977) who same  indicated  both the spheroid significant  and  difference  t h a t Kormendy  found  procedure.  results  the  disk  become  shallower.  i f t h e d i s k was modeled  <15".  radii.  The  underlying  as  i n h i s F i g u r e s 3 and 6 ( r e p r o d u c e d i n  radii  A  disk  off  profiles  Figure  10  he of  a d i s k t h a t d e v i a t e s f r o m an e x p o n e n t i a l a t  i n the i t e r a t i o n  procedure, the  resulted  profile  a  of the  cutting  T h i s t y p e o f m o d e l was m o t i v a t e d by t h e f a c t  in  more  i n t h e r e s u l t s of the decomposition i s  presents  show  his  presented h e r e , however,  at  work)  of  t h a t t h e s p h e r o i d became s t e e p e r w i t h  sharply  this  small  The  t h a t the best f i t t i n g decomposition  was.obtained  here  a n a l y z e d s e v e r a l r e d compact  successive i t e r a t i o n s . I n the r e s u l t s  profile  the  NGC  component.  with those galaxies  for  r e g i o n o f t h e r e d image  t h e r e f o r e b e s e e n t o be m a r g i n a l l y  at  residuals  c o m p o n e n t s o f t h e r e d and v i s u a l i m a g e s o f  1566. F o r t h e r e d i m a g e , o~=.019, and <o=.016.  convolved  sum  of  the  t h a t was o v e r - l u m i n o u s  two  that,  components  b e t w e e n 5" and  26  15",  compared t o t h e  not  suggest  discussed  observations.  a c u t o f f i n the  p r e v i o u s l y , the  exponential  data presented  disk at small r a d i i .  trend  with successive  The  of  the  iterations  disk  here  However,  becoming  i s o b s e r v e d . But  intermediate  successively exponential  radii,  under-  rather  model.  By  over-luminous  luminosity  inside tbat radius,  from  observed  component c o u l d The  profile,  not  manner  as  11, and  the corresponding  Table  6  contour red  and  #  p l o t t h a t the  image.  The  the  to a s c r i b e a l l the  after  subtracting  as  excess  the  bulge  to a Gaussian model. 1566  r e d i m a g e . The  plotted  to  is  t o t h e n u c l e a r component. Such a  be f i t t e d  v i s u a l i m a g e o f NGC the  compared  p o s t u l a t i n g a disk c u t o f f at r^5",  Kormendy d o e s , i t w o u l d be n e c e s s a r y  the  model  as Kormendy f o u n d , t h e d i s k p r o f i l e  and  as  less  than d e r i v i n g a s i n g l e under-luminous region i n the d i s k at  do  was  analyzed  contour  in  p l o t i s shown i n  luminosity profile i s i n Figure  12.  I t can  v i s u a l image i s much  v i s u a l i m a g e was  the  be  same Figure  tabulated  in  seen from  the  noisier  than  smoothed w i t h a 4x4  the  running  mean s m o o t h i n g . The final 15.  initial  bulge p r o f i l e  disk p r o f i l e The  final  i n Figure  disk  e x p o n e n t i a l than the the  visual  image  c a n n o t be c o n c l u d e d i n t h e v i s u a l and  is  shown  14, and  profile  the f i n a l  deviates  red image does.  in  even  Figure  13,  bulge i n more  the  Figure  from  the  However,  as  mentioned,  i t s e l f i s n o i s i e r than the  red  image so i t  real  difference  that t h i s red d i s k s .  represents  any  27  The is  seeing  Gaussian  of  i s plotted in figure  t o r =2",  with  the  visual  image b u l g e  same manner  as  the  a bulge  model w i t h  with  seeing  disk  the  iteration Figure  bulge  profile  diameter  (FWHM)  corrected f o r seeing  effects  disk  bulge  a  good  This convolved  profile,  frcm  residual  the  disk  distribution  given  The  nucleus,  residual  bulge  was  found of the  f i t  profile  that form  to  the  final  is  shown  in  and  the  disk  Again,  The  f a i n t n e s s of the  of  the  magnitude  nuclear  the  fitted  obtained from t h e  nucleus  discussion  observations component  by  subtracting  the  i s shown i n F i g u r e  17.  by  a  an  by  surface  subtracting  brightness  8.5  of  NGC  inside  of the  et 1566  an  8^'5  in  nuclear  section  aperture  Smith  profile,  is significant  in  of  the  convolved  o b s e r v a t i o n s , i s shown i n  f o l l o w s a Gaussian  variability  inside  luminosity  observations, is  nucleus  observed  From  the  the  obtained  by  16.  total  It  surface brightness  provided  profile.  residual  convolved  1566.  image.  15.  The  The  was red  convolving  in  This  a seeing  16.  2^48. The  in  out  profile  i s .19 al  of the  brightness  2,  the  mag  fainter  of  observed now  Thus,  NGC V than  star-like  f o r a b o u t 5% o f  aperture.  form  consideration  ( 1 9 7 2 ) . . The  accounts  Figure  i f  the the  28  b r i g h t n e s s v a r i a t i o n i s e n t i r e l y due to the s t a r - l i k e n u c l e u s , then  this  nucleus  must  have been about  6 times b r i g h t e r i n  1972 than i n 1977. C o n s i d e r i n g t h a t the data of Quintana et a l (1975) i n d i c a t e s t h a t the b r i g h t n e s s v a r i a t i o n s occur on scales  of  one  year  or  l e s s , the v a r y i n g component  s m a l l , so i t would seem that the most variation  is  likely  source  time  must be of  the  the s t a r - l i k e nucleus. B r i g h t n e s s v a r i a t i o n s o f  f a c t o r s comparable to t h i s have been noted sources, s p e c i f i c a l l y  QSO's.  in  other  compact  21  /OO  Figure 3: Isophotal contours for the red image of NGC 1566. Contour values and corresponding r a d i i are given in Table 5. The dashed-line region indicates the region corrected to remove the foreground star, which was then used to determine the seeing profile.  30  Figure 4: Luminosity p r o f i l e f o r the red image of NGC 1566, derived from the values i n Table 5. The s t r a i g h t l i n e i s the i n i t i a l d i s k p r o f i l e used i n the i t e r a t i o n procedure, and i s described by the equation At*  " H.57  +•  .Of85r  31  Table 5 Surface B r i g h t n e s s D i s t r i b u t i o n Of The (arcsec) 0.73 0.92 1.09 1.25 1.41 1.56 1.71 1.87 2.03 2. 20 2. 38 2.57 2.79 3.03 3. 30 3.60 3..S4 4.33 4.77 5,. 29 5.89 6. 51 7.25 8.03 8.99 10. 14 11.55 13.49 15.43  E Image Of NGC (mag/a" )  15.79 15.88 15.97 16.06 16. 15 16.24 16.33 16.42 16.51 16.60 16.69 16.78 16.87 16.97 17.06 17. 15 17.24 17.33 17.42 17.51 17.60 17.69 17.78 17.87 17.96 18.05 18. 14 18. 23 18.32  1566  32  2.0  Figure 5: Residual bulge profile obtained by subtracting the i n i t i a l disk from the observations. The straight line i s the i n i t i a l bulge profile, described by the equation which was subtracted from the observations in the iterative procedure.  33  17.91  /?.0l-\  Onoj/a")  11%  /fci-  1 0 . 0  3 . 0  1  1  6 . 0  9 . 0  RflD F i g u r e 6: F i n a l d i s k p r o f i l e d e s c r i b e d by t h e e q u a t i o n jU.  A  1— _  +  15.0  (flRCSEC  (8th i t e r a t i o n ) .  ~- i 7. 9</f  1 2 . 0  .03/?7r  The s t r a i g h t l i n e i s  16  jy  /57/H  fit.  S02l-\  T  1.2  1  r  1.4  1.5  r 1.8  1  2.0  RXX0.25 (flRCSEC)  Figure 7: NGC 1566 red image. The dots (•) indicate the f i n a l (8th) iteration bulge profile. The straight line i s described by the equation The points lying below the straight line at 1.6 r 1.8 are also underluminous on the disk profile of Figure 6. The crosses (*) indicate the convolved bulge profile, obtained from the procedure described in section 3.  -  35  n3(A  o. Figure 8: Red star image and nucleus of NGC 1566. The dots(») denote the star profile. The straight line i s described by the equation = /C.505 * -GSO?^ The crosses(*) denote the residual profile, and the corresponding straight line i s described by  it. 7/H 0  0  1 3.0  1 6.0  1 9.0  RflD (RRCSEC)  1 12.0  1 15.0  1 18.0  F i g u r e 9: R e s i d u a l p r o f i l e , o b t a i n e d by s u b t r a c t i n g the c o n v o l v e d b u l g e p r o f i l e f o r t h e r e d image from t h e o b s e r v e d p r o f i l e . The s t r a i g h t l i n e i s t h a t o f F i g u r e 6.  37  r (arcsec) Figure 10: From Kormendy (1977). The top figure shows the decomposition using the iterative procedure. The bottom figure i s the p r o f i l e obtained by f i t t i n g the disk to an equation of the form  Figure 11: I s o p h o t a l contours f o r the v i s u a l image of NGC 1566. Contour values and corresponding r a d i i are given i n Table 6. The dashed-lines i n d i c a t e the r e g i o n c o r r e c t e d to remove the foreground s t a r .  39  /72/-i  mi  A  K K  MA  n-iiA  10.2.10 . 0  1  1  3 . 0  6 . 0  1 9 . 0  RflD CflRCSEC)  12.0  15.0  16.0  Figure 12: Luminosity profile for the visual image of NGC 1566, derived from the values in Table 6. The straight line i s the i n i t i a l disk profile used i n the iteration procedure, and i s described by the equation Mv-  t  .0?0/r  no  Table 6 Surface B r i g h t n e s s D i s t r i b u t i o n Of The V Image Of NGC 1566 r  (arcsec) 0.89 1.28 1.58 1.86 2. 11 2.36 2.60 2.85 3. 10 3.36 3.63 3.92 4. 24 4.59 4.98 5.39 5.85 6.33 6.8 5 7.46 8.09 8.75 9.45 10.26 11. 18 12.42 1 3. 6 2 1 4.88 15.99 17.45  (mag/a) 17. 30 17.40 17.49 17.59 17.68 17.78 17.87 17.97 18.07 18. 16 18.26 18.35 18.45 18.54 18.64 18.73 18.83 18.92 19.02 19.11 19.21 19.31 19.40 19.50 19.59 19.69 19.78 19.88 19.97 20.07  F i g u r e 13: R e s i d u a l b u l g e p r o f i l e f o r the v i s u a l image o f NGC 1566, o b t a i n e d by s u b t r a c t i n g the i n i t i a l d i s k from the o b s e r v a t i o n s . The s t r a i g h t l i n e i s the i n i t i a l b u l g e p r o f i l e , d e s c r i b e d by the equation  Xv'-  +  (..15  HA.  tficA m a  Qo.cxA  J04J  °'°  5  6  "° RRD lA&SEC)  1..  Figure 14: F i n a l disk p r o f i l e f o r the V image (12th i t e r a t i o n ) the straight l i n e i s described by the equation Mv  - /f.632  t  .01l7  r  15.71  Figure 15: NGC 1566 visual image. The dots(») indicate the f i n a l (12th) iteration bulge profile. The straight line i s described by the equation X  v  = /2.316- *  H.SMr*  The crosses(<) denote the convolved bulge profile, obtained as described in section 3.  tt%-\  jQ.%-\  0.0  1 7.0  Figure 16: Visual star image and nucleus of NGC 1566. The dots(») the star profile. The straight line i s described by the equation The crosses(«) indicate the residual nucleus, and the corresponding straight line i s described by  fl%-\  JO.%-\  0.0  1  1  1  1  1  3.0  6.0  9.0  12.0  15.0  RAD  (flRCSEC)  1  18.0  F i g u r e 17: R e s i d u a l p r o f i l e f o r the V image, o b t a i n e d by s u b t r a c t i n g the convolved b u l g e from the o b s e r v a t i o n s . The s t r a i g h t l i n e i s t h a t of F i g u r e 14.  o  46  4.  Discussion  It  i s necessary to preface a discussion  derived  here with  extend  to  r ^17".  examine the determine NGC  disk  problems discussed  fit  the  profile.  i n the  p h o t o m e t r y would be this  that  allow  the  The  b u l g e , on  begins  the  increase 1a and  2 can  large  radii.  be  the  et  disk,  v i s u a l and  al  the  to  (1972)  from  red  of the  of  the  disk  bulge,  and  compare  i m a g e s , and  luminosity visual  to  disk  and  profiles  and  red  i s redder at l a r g e r  bluer.  The  disk  reddening  of  radii.  component  seen i n the  is  disk  p r o f i l e a t r >4i!5. Thus  increasing distance  a t t r i b u t e d to the  the  galaxies.  brightness  i n v-r c o l o r with  d e r i v a t i o n of  I t i s of i n t e r e s t t o  o t h e r hand, i s  t o dominate the  the  of t h e s e components t o the  slopes  of  of  Smith  defined  the  most s u r p r i s i n g f e a t u r e  that  better  profile  p r o f i l e s obtained  well  derived.  similarity  indicates  luminosity  to  value.  difficulty,  comparison of t h e  profiles  able  i n consideration  from the  b u l g e components of normal s p i r a l The  u s e f u l t o be  only  e x i s t i n g photometry, attempting  of d o u b t f u l  procedure  the  very  observations  Appendix r e g a r d i n g  s t r u c t u r a l components of  consider  the  H o w e v e r , no  derived  n u c l e u s c o m p o n e n t s t o be the  be  i s a v a i l a b l e , and  data to a disk  iterative  would  p r o f i l e from the  Despite  that  structure  at l a r g e r v a l u e s of r , i n o r d e r to  i n V o r E,  luminosity  warning  Jt  profile the  1566,  the  of the  the  Figures disk  at  47  The  magnitudes  of  the  bulge  aperture,  from the c a l i b r a t i o n  E=11.78.  For'  the  disk,  of  component section  V-12.42  and  2  inside are  r  R=10.62  a  40"  V=12,54,  inside  this  aperture. The 1973)  distance estimated  i s 11 Mpc. °<' = 1.81  kpc  a  length  °^' = 1.42  within  range  galaxies  of  given  the by  kpc  However, t h i s  for  (2), a disk  scale  from Eguation  visual  who  Vaucouleurs,  image. T h i s i s  late-type  spiral  notes g e n e r a l l y  systems  of  type  Sbc  s c a l e l e n g t h c o r r e s p o n d s t o a b o u t 30 24"  f o r the  visual  image. T h e r e f o r e  low or for  ,/  i t is  (1973) d e r i v e d a l u m i n o s i t y p r o f i l e f o r  B image o f NGC  1566  from the  described  his  Appendix  in  Appendix to t h i s distribution  to  work. He  magnitude a p e r t u r e B,  fitted  in  the  but  systematic  galaxy, although departures  exponential  and an  relation,  b r i e f l y discussed exponential  in  account f o r a  bulge  indicates  the  observed  presence  of  B<j(/>)  a  and  Hubble type  disk derived  by  of the  the  kpc.  small the  significant  c o n t r i b u t i o n from a s p h e r o i d a l component, c o n s i s t e n t w i t h intermediate  as  structure  as n o t e d by d e V a u c o u l e u r s , "The between t h e  the  luminosity  t h e p r o f i l e , w i t h a s c a l e l e n g t h o f 3.3  However, t h i s a n a l y s i s d i d n o t  The  (5)  t o d e t e r m i n e whether t h i s i s a t r u e d i s k component.  DeVaucouleurs  pure  (de  for  (1975),  later.  impossible  the  lengths  Freeman  i m a g e , and  for  scale  o f °< , l e s s t h a n 2 k p c ,  red  1566  f o r t h e r e d i m a g e , and  values  the  NGC  T h i s i m p l i e s , from E g u a t i o n  l e n g t h of scale  for  the  galaxy."  d e V a u c o u l e u r s was  fitted  o v e r a much  48  larger region over  more  ( 3 minutes of a r c ) , so t h a t  than  h i s data  3 disk scale lengths. I t i s interesting  t h e i n n e r 60" o f t h e p r o f i l e  region  the  CCD  distribution.  6" a n d 18" i s u n d e r - l u m i n o u s compared t o  between  t h i s inner exponential, i n contrast to from  data,  but  the  the  profiles  photographic  The  derived  data  d e V a u c o u l e u r s does not r e s o l v e t h e i n n e r r e g i o n s to permit  used  sufficiently  nuclear  point source  f o r e a c h image c l o s e l y  part of the star  profile  follows  so t h a t t h e  d i f f e r e n c e i n s l o p e between t h e n u c l e a r components o f t h e i s attributable  to  seeing  magnitude, using t h e c a l i b r a t i o n the  V  magnitude  i s  magnitude of t h e bulge E=12.63.  by  d e t a i l e d comparison of t h e p r o f i l e s .  the slope o f the Gaussian  images  that  he d e r i v e d , p l o t t e d i n h i s F i g u r e  1 1 , shows a s e c o n d g u a s i - e x p o n e n t i a l l u m i n o s i t y The  extends  16.73  effects.  o f s e c t i o n 2,  giving  inside  The  a  a  10*  nuclear E  i s  16.03  and  V-E c o l o r o f 0.7. The aperture  i s  The d i s k b r i g h t n e s s i n s i d e t h i s a p e r t u r e  E=13.33, s o t h e n u c l e u s  two  i ssignificantly  V=13.61,  i s V=15.05,  bluer than  either the  disk or bulge. From t h e c a l i b r a t i o n the nuclear effective at  the  component  g i v e n by J o h n s o n  i s  1.166x10~  2 9  (1966),  W  m  Hz  - 1  w a v e l e n g t h o f t h e E b a n d , and 7 . 7 4 3 x 1 0 ° W m -3  effective  wavelength  of  which  i s  derived by Shields ;  ccmparable  to  at the -2  Hz"*  t h e V band. I f the n u c l e a r  continuum i s non-thermal, the corresponding e<=-1.714,  -2  the f l u x of  the  a n d Oke (1975) f o r NGC  s p e c t r a l index  spectral 1068..  i s  i n d e x o f -2  49  The  c o l o r diagrams  center,  due  to  the  ( F i g u r e s 1a and fact  that  the  2) bulge  c e n t e r . As d i s c u s s e d i n s e c t i o n 2, t h i s effect  due  to  1566  is  a  barred  spiral  luminosity  p r o f i l e s or the c o n t o u r  galaxy.  profiles  is  component this  appear  Perhaps  due  of  reddened  i s redder probably  obvious  to  the  to  the  the  at  the  not  an  asymmetry i n in  that  inner disk.  does  the  not  than the  component  of  a  t h e d i s k shows the o p p o s i t e e f f e c t  the outer d i s k i s redder NGC  is  d u s t b e c a u s e t h e r e i s no  t h e c o n t o u r s , and  show  g a l a x y . However, t h e  significantly  affect  shapes i n the i n n e r  wriggly  behavior  contribution  s t r u c t u r e w h i c h has  of  bar the  regions  of t h e  this  disk  additional  n o t been c o n s i d e r e d  in  analysis. Another important  aspect  to c o n s i d e r i s the  effect of  emission  l i n e s on t h e p h o t o m e t r y . Csmer e t a l (1974)  a  through  flux  t h e H°< e m i s s i o n line,  by  Johnson  more  a 10" a p e r t u r e o f 7 . 1 x 1 0 o f NGC than  (1966) t h e f l u x  aperture  is  c o n t r i b u t e no A final structure  5.296x10 more t h a n point  to  determined  1566. a  T h i s was  f a c t o r of o f t h e CCD  - 1 1  ergs cm  - 2  1% o f t h e be from  2.  ergs cm  measured - 2  strongest  strongly  s-»,  of  the  same  so t h e e m i s s i o n  lines  flux. before  method  is  accepting that  the determination of the p o i n t source  d e p e n d e n t on t h e a c c u r a c y  for  1  With t h e c a l i b r a t i o n  the  dominates i n b r i g h t n e s s i n the c e n t r a l r e g i o n s of the Therefore,  s'  measured  r e d image t h r o u g h  considered this  the  - 1 3  the  w i t h which  the  the bulge  galaxy.  component i s bulge  has  50  been  determined.  spheroidal  The  bulge  de  structure  approximation.  However,  work  King,  (see e .  since  g.  i t i m p l i e s an  appears  to hold  correction  Vaucouleurs  as  is has  to regions  f o r seeing  empirically  relation  well within (see  the  out  (1979) used  r  law  luminosity  profile  NGC  3379. They d i s c o v e r e d  which  could  dispersion function a  of  of  1'i3, so t h a t nucleus.  center  usefulness  law  of  more r e a l i s t i c  as  of  NGC  component.  deVaucouleurs  used  a c c o u n t e d f o r by  i t i s reasonable  source  i n the  derived  limitations different exhibit.  physically  which this,  to  elliptical  these and  objects  seeing  the  profile^ a  at  point  that  the the  increased  i f a  (1966)  noted,  were  though,  model, which clusters,  galaxies are  because of the  so  r=0,  King  star  a  a t t r i b u t e d to  fact  this  for  with  the  of the  be  model  galaxy region  but  to  would be  (1978), t h a t  E1  excess  procedure. I t should  applied  that  convolved  the  seeing  by  King  a  core,  be  it  Recently,  central  meaningful  drawn  r=0,  previously,  derived  when  of  this  in consideration  isothermal  dynamics  noted  does f o l l o w t h e  conclusions  by  as  not  at  disk, after  dispersion for  tc attribute  an  Because  the  of  the  excess could  model, s u c h as  cut  from  1566  i s net  the  the  in  a Gaussian  However,  Eut  iteration  pointed  excess  3i'7, compared t o  star-like  Gaussian that  be  an  hold  1979).  Capaccioli  t r y t o f i t the  previous  Nonetheless,  however, d e V a u c o u l e u r s and to  good  in  seeing  Schweizer,  the  a  cannot  central density.  effects  describing  been p o i n t e d  1978), t h i s  infinite  law  due  to  was has the  expected  to  difficulty  of  51  generating in this  K i n g m o d e l s , no a t t e m p t  h a s been made t o  use  them  work.  Table  7  s u m m a r i z e s t h e p h o t o m e t r i c d e c o m p o s i t i o n o f NGC  1566.  T a b l e 7 Model Parameters  j_ p o i n t source a M-Mo * <r  V image ^  R image  V star  * =  R star  Mt= H..SOS  _ /tf,259  SEEING -  F o r NGC 1566  z  .(.19  „  <* = .G502 SEEING_  (FN/YHMT ''SI Bulge component  Mo =/2.%%3.  " ' A " * *  fi  disk comp on en t.  H° =/?•<# 3 _2.  j3 -1-73.1  A> =/7.9?9  b '.03/97 - loi u tencjth "/•«/ fyZ-  52  Chapter  NGC  j.  J068  Introduction  NGC of  1068  12  was  galaxies  included which  in Seyfert*s  he  emission  most c o n s i s t a n t  characteristic  stellar NGC  of  including several  H y d r o g e n , and  2400 km/s The  (He  next  done  and  Prendergast  t o about  25"  from the  the  disk  plus  of the to  be  of the  nucleus, a unifrom  galaxy, about  In studied  the at  an  and  limiting past all  the 15  1068  (H was  derived on  and  the  3600 km/s NGC  measured  lines,  for  luminous 15  the  lines Balmer  lines  ranging  lines). that  the  of  Burbidge,  r o t a t i o n curve  spectra  from  regions  a mass d i s t r i b u t i o n c o n s i s t i n g o f  estimated  2.6x10»o H©.  Seyfert  widths  based  spheriod,  r o t a t i o n curve of  constraints  exceedingly  (1959) who  derived  "...many  being  on  center,  as h a v i n g  list  i n the n u c l e i . . . t h e i r  I I , X4686) t o  study  original  localized  forbidden  derived  Eurbidge  near  lines  s e m i - s t e l l a r nucleus..."  1068,  lines from  or  (1943)  characterized  high-excitation  in  3  the the  By  latter total  studying  a large  years  wavelengths.  the  mass w i t h i n the  central  nuclear  within  mass t o  NGC  1068  A  review  inner this  effect  on  mass,  they  about 3x10?  a  20"  region  the  shape placed  M. 0  has  been  extensively  of  the  literature  53  presented here,  since  the  Spectroscopic  the the  and  gas.  the  the  H°(  and  Parker  from the  excitation spectrum moving gas  the  lines  done  following optical  X-ray.  f o r the  arise  that  they from  o r f r o m uv  electron  volume  of  and  concluded, of order  200  distributed. line  intensities  were a l m o s t t w i c e  c a l c u l a t e d a very  derived  the  parsecs for  t o be  that  there  i n agreement with  line  the  of  o f 20  region  reported  suggested  forbidden  clouds,  (1965)  density  mechanisms, could  the  be  spectrum  observed  uniformly  (1943)., and  also  the  is  i s not  jll i f ]  They  comparing  derived  and  an e s t i m a t e  emitting  region  v a r i a t i o n s i n the nucleus, by  studied  derived  of the  gas  m e a s u r e d by S e y f e r t decrement.  DV  They d e t e r m i n e d a v a l u e  emitting  that the  will  polarization,  t e m p e r a t u r e , as w e l l as e s t i m a t i n g  O s t e r b r o c k and for  and  effective radius  parsecs,  into  r a d i o , and  (1965)  1068,  emitting  since  i f , as  Observations  Pronik  o f NGC  divided  studies,  observations,  D i b a i and  density  are  spectroscopic  photometry, IE  nucleus  i s most i n f o r m a t i v e  investigations  categories:  (a)  1965  from the  large  were  Dibai  and  collisional synchrotron  Balmer density Pronik,  IK f l u x w i t h  r a t i o s . In discussing suggested  those  that  the  possible emission  e x c i t a t i o n from radiation.  that  the  54  Walker  (.1968)  obtained  emission  features  concluded  t h a t the emission  of  diameters  that  the  source.  Walker  outside  the  r  measured  w i t h i n 25"  which  from  and  from  at l e a s t  masses o f  the  four 10 -10 6  r o t a t i o n curve  c e n t e r , and  both  the  which  than the n u c l e a r  indicated  the  resolved  he  clouds M,  7  so  s  continuum for regions  rotation  circular  and  motions f o r  >30". (1968  and  substantial  reddening  necessarily  in  if]  the  )\4072 and density  observers  be  to dust  and  lines  spectrum  In from  c o u l d be  a  the  emission by  later  account  using the  there  was  but  not  the  reguired  ratio that  of  that the reddening  However, t h e  t o 6800A, and  explained  calculating  determinations  suggested  study,  that lines,  therefore  temperature  c o u l d not  3700A  determined  continuum,  i n the nucleus.  decrement.  that  in  m o d i f i e d . He  \s if]  the  1971)  )\10320, which  electron  by  from  region i s larger also  which  components,  arises  parsecs,  nucleus,  Wampler  [s  several  -200-350  emission  expansion  into  spectra  observed f o r the  Koski  (1978)  the  earlier was  reddening very  of  due from  l a r g e Balmer observed  measured a B a l m e r  the  decrement  amount o f r e d d e n i n g  derived  Wampler. Souffrin  (1969)  and  Andrillat  observed  ionization  determined  t h a t the  probably  due  to  eguivalent  width  of a b s o r p t i o n l i n e s  nonthermal  and in  radiation,  Souffrin  (1971)  the  nucleus  was  Ey  fitting  the  i n the nucleus  with  those  55  calculated  for  amounts  of  dominant  star  various  nonstellar type  was  appreciably  reddened.  1975)  measured  they  K-M,  the  NGC  but  because  these  and  Later  high-intensity not  populations  continuum,  reported 4151,  stellar  concluded  that  the  the  continuum  was  not  (Andrillat  spectrum  g a l a x i e s had  and  from  Collin-Souffrin,  7000A-11000A,  )N\9069,9532 i n NGC  i n other Seyferts.  two  different  they  that  [~S III)  and  They s u g g e s t e d  less  stellar  and  1068  and  this  was  contribution  than  the other Seyferts s t u d i e d . Anderson  (1970) compared t h e  profiles,  and  for  1068,  NGC  confirmed modeled  The  that  age  a recombination spectrum  (1974), with  by  Martin  estimate  distribution solar  was  who  to  other  producing  studied  (1974), and the  with t h a t  line  indistinguishable  Seyferts,  and  also  galaxy.  He  o f t h r e e components: the  observed  a  emission  continuum.  classified  for  permitted  II absorption f o r t h i s  forbidden  composition  5.05x10  contrast  essentially  nuclear region to c o n s i s t  is,  width,  were  component, n e b u l a e and  Weedman  in  they  a v e r y s t r o n g Ca the  stellar lines,  found  f o r b i d d e n and  further  NGC  lines by  1068 and  by  of other s t e l l a r  f o r the s t a r s .  The  Khachikian  as a S e y f e r t  Balmer l i n e s  Schild  galaxy  by  (1972),  who  comparing  type  of the  2, same  derived the  systems,  and  energy  assuming  d e r i v e d age  an  a  i s of  order  Ii]  lines  years.  Eilek  et a l  (1973) o b s e r v e d  the blended  H^,  [N  56  and  compared  of  Osterbrock  and  found  over the  later  the  Parker IK l i n e  paper  emitting  (Glaspey  over about  had  varied  Alloin  and  Sareyan  no  through  narrow i n t e r f e r e n c e f i l t e r s ,  results that than  the  1068  normal  from  with  t h e . js the  s  e  also  cm  and  stellar  In  the  the  the  used  the  was  tij$,  data  nucleus.  contribution  a  continuum, to  Their  Collin-Souffrin  (1975) r e p o r t e d a 40$ and  to  1972.  l i n e s and  - 3  giving  giving  - 3  suggested  compared  less  emitting cm  e  Oke  1965  if]  N ~ 800  N ~2x10  had  and  between  modeled  with A n d r i l l a t  in  that  reported.  for  e m i s s i o n l i n e s , and  conditions  width  cm.  7  was  fluxes  and  and  (1975)  i n the  nucleus  galaxies.  Shields flux  physical  concurred  NGC  [b I I I ]  blend  jjb I I I ] l i n e  variation  (1974) measured  )\3726,  10*  the  that  determined  of o r d e r  1976) ,  y e a r , and  the  in intensity  which t h e y  [o i f ]  determine  and  from  al,  t h r e e months, w i t h  They d e c o n v o l v e d  r e g i o n was et  one  over  (1965).  t h r e e month p e r i o d , of the  observed  s p e c t r a , taken  and  that  the size  their  the  Based [A ivj  decline i n  rise  to the  and  jo  III]  lines,  o f two  |j5 I l j l i n e s ,  nitrogen  solar  values,  was from  overabundant an  one  one  with  lines.  They  NGC  1068  in  analysis  they  zones:  and  to the h i g h e r e x c i t a t i o n  that  H*  on t h e d e n s i t i e s d e r i v e d  r e g i o n as c o n s i s t i n g rise  the  of  the  line  intensities. Yankulova and  computed  (1975) used  theoretical  a power law  emission l i n e  central  ionizing  intensities.  source  He d e r i v e d  57  a diameter of ^ 1 4  parsecs f o r the emitting  E i c h s t o n e and Morton region  3880A-4120A.  region.  (1975) measured t h e s p e c t r u m  They  calculated  a velocity  150*50 km/s  f o r the s t a r s i n t h e n u c l e u s from  the  )\4046  Fe  14x10  8  r "140  I M©  absorption  f o r the central  line.  region  They  using  a  in  the  dispersion of  measurements  derived nuclear  of  a mass o f radius  of  parsecs. Grandi  (1978)  was s l i g h t l y  blueshifted  He s u g g e s t e d t h i s region  near  ionization  measured  i s due  the  compared to  continuum  i o n s expanding  [ F e Xi] X 7892 w h i c h he  to the other emission l i n e s .  absorbing source,  toward  reported  dust so t h a t  us c o n t r i b u t e  confined only to  to  those the  a  high line,  whereas t h e d u s t d o e s n o t e x t e n d o u t f a r enough t o o b s c u r e t h e low  ionization  ions.  Absolute has been  published  3500A-4300A, and  Sareyan  (1975)  spectrophotometry  in  by W a l k e r  Schild  of t h e continuum  o f NGC  (1968), f o r the wavelength  (1972) f o r t h e r a n g e  3500A-6000A,  (1974) f o r t h e r a n g e 3300A-6300A, S h i e l d s the  r a n g e 3300A-11090A, K o s k i  3700A-6800A, and d e B r u y n 3140A-10680A.  .(b). P o l a r i z a t i o n .  and  Sargent  1068 range  Alloin  and  Oke  (1978) i n t h e r a n g e  (1978)  in  the  range  58  Polarization NGC  1068  was  polarization ultraviolet Elvius  of t h e  first i n the  and  Hall  well,  decreased  with  and  V and  aperture  with  polarization  nucleus. the  that  and  high-freguency  in  again  the  degree  white  of  measured  3%  13%  at  confirmed blue  of  suggested  and  by  wavelength  polarization  paper  light  is 3%  different  correlation  noted  which et  B b a n d , and  size, in  the  polarization  polarization  (Dombrovskii  the  aperture  f o r the  of  that  concentrated  component  i n the  the  also  polarization  for  decreasing  t h a t the  synchrotron  light,  confirmed  a v a l u e of  1% p o l a r i z a t i o n  the  nucleus  about  (1968) measured  with  polarized  d e t e c t e d . In another measured  and  derived  who  was  measured  Hagen-Torn  increased  They  the  wavelength.  wavelength,  t h a t the  nucleus,  noted  They  (1964),  polarization who  B filter,  polarization  Walker  from  w a v e l e n g t h r e g i o n , and  (1965),  and  sizes.  indicating  yellow  increasing  Dombrovskii the  r e p o r t e d by  w a v e l e n g t h s . The  r e g i o n as  in  optical radiation  was had  al, .1%  due not  1971)  to  in a  been they  i n t h e V and  B  bands. Visvanathan U, in of  B,  Oke  (1968) measured t h e  V and fi f o r 3 a p e r t u r e  the  polarized  flux.  stellar  the thermal  sizes,  and  found  They modeled t h e  a n o n t h e r m a l component  thermal, in  and  causing  component. By  component i s  the  polarization no  nucleus  constant  variability as  consisting  polarization,  assuming t h a t the with  in  and  a  polarization  wavelength,  they  59  derived  the  component,  energy which  wolstencroft arose  from  distribution  resembled  (1970)  surrounding  the  that  instead  scattering  by  of  dense  From  on  the  observations  1.5), and the p o s i t i o n Kruszewski flux  for  a  QSO.  shell  degree  nonthermal Nandy  and  polarization  of  dust  of  grains  polarization,  (39.9% f o r a nucleus of  diameter  angle.  (1971) r e p o r t e d an almost  apertures  the  t h i s model they were able to  reproduce the p r e v i o u s l y c a l c u l a t e d based  for  suggested that the a  nucleus.  curve  larger  than  constant  7", and f i t t e d  polarized a power law  '.3.X  f u n c t i o n , of the form Fj, = rvt/ was  inconclusive  , to the measured f l u x . His  i n determining whether the p o l a r i z a t i o n  v a r i e d . However Babadzhanyants et a l (1972) degree of p o l a r i z a t i o n had B  band.  The  with  stated  polarization  due  to  the a d d i t i o n a l r a d i a t i o n 9.5%  p o l a r i z a t i o n , and another  a  p o l a r i z e d . They spectrum  Because  degree of p o l a r i z a t i o n , they suggested t h a t  particles  were  being  brightness  component with a steep  g i v i n g r i s e t o the observed i n f r a r e d excess. high  the  d i r e c t i o n d i d not change, so they  modeled the nucleus as having a f l a t power law 8%  that  had  v a r i e d between 1.25Sf and .5% i n the  concluded t h a t the observed change was increase,  data  ejected  from  the  with  spectrum, of  the  relativistic  nucleus  in  cne  direction. The  g u e s t i o n of the source of the p o l a r i z a t i o n was  considered by S i k u l i n  et  al  (1971)  who  reported  again  circular  60  polarization  of  synchrotron  source  Subsequently, 1972,  about less  several  1%  in  likely  the  nucleus,  as a cause  observers  polarization  in  NGC  (Nordsieck,  1068,  1972,  observe  the  circular  polarization  polarization.  in  with negative  appeared  t o have  whereas  the  [o.IIlJ,  which was p o l a r i z e d  lesser results,  the  they  than  is  i n t u r n surrounded  angle  source  these  They  The p e r m i t t e d as  at a different lines.  angle  and  To a c c o u n t  as c o n s i s t i n g  surrounded  by a d u s t  i s by E l v i u s  lines  to  a  f o r these  o f a continuum shell,  which  emission.  (1978) who f o u n d  that  regions outside the nucleus are  he d e t e c t e d a c l o u d n o r t h e a s t o f t h e  10" l o n g , w i t h  48  polarization,  that the f a rinfrared  and  position  r a d i a t i o n and  which have been d e t e c t e d i n NGC 1068  arise  from  clouds. Polarization  Capps  measured  by a r e g i o n o f f o r b i d d e n l i n e  1 3 5 ° . He s u g g e s t e d  CO m o l e c u l e s  they  except f o r  In particular,  about  detector,  l i n e s had no p o l a r i z a t i o n ,  not only the n u c l e u s , but a l s o  nucleus,  results.  continuum,  most r e c e n t s t u d y  polarized.  Gehrels,  the  modeled t h e n u c l e u s  Balmer e m i s s i o n  lines.  polarization  the permitted  and  The  same  forbidden  degree  In a d d i t i o n ,  the emission  a  1972) l o o k e d f o r  However, i n 1976 A n g e l e t a l , u s i n g a more s e n s i t i v e did  made  of the polarization.  Kemp e t a l , 1972, L a n d s t r e e t and A n g e l ,  circular  which  (1974), stated  in  the i n f r a r e d  was measured by Knacke and  who made o b s e r v a t i o n s a t 3.5^, 10.2/i, and 18.4/f.  t h a t t h e observed  polarization  c o u l d be  explained  61  by  nonthermal  source, be  there  uas  also  e x p l a i n e d as a r i s i n g  combination  o f t h e two  Eadio Bologna 10.6 49  e m i s s i o n , i f , i n a d d i t i o n t o the observed  cm,  each  and  case the  (c)  UBV  from  14  Sramek  not c o r r e l a t e  grains,  or  also by  a  have been p r e s e n t e d  by  Maltby  and  (1967) a t (1974) a t  Seielstad  18 cm, 11.1  was  in position  Strom  and  at  (1973)  at  cm.  In  3.7  l e s s than angle  (1966)  1.535, and  with the  in  optical  measurements. .  Photometry  (1954) c a l c u l a t e d to  4i1,  photomultiplier  based  tube.  measured  OBVEIJHKL  diaphragm.  Their  The  radiation  273,  t h e r e f o r e they  mn  on  Pacholcyzyk  diagram  and  for  NGC  showed t h a t  long wavelengths  excess  was  suggested  in  shown t o be that  i n the nucleus of the  Sandage  f o r 3 aperture sizes, measurements  fluxes  flux  e x c e s s a t s h o r t and  component  observations  Seielstad  and  by  data could  mechanisms.  p o l a r i z a t i o n . observed  did  Petit  and  ffardle  infrared  scattering  (1965) a t 21 cm,  Eerge  and  general  from  polarization  et a l  cm,  a compact s o u r c e . The  10/f I E  there  ranging  obtained  using a  Wisniewski  (1967)  1068 NGC the  through 1068  observed  similar was  had  a a  15" large  range.  to that of a  3C  guasar-like  galaxy.  (1967) p u b l i s h e d OBV  photometry  f o r 5 apertures,  62  ranging  from  4l'9-20", and  is,  the  magnitude  that  the  colors  because In  the  Vaucouleurs  a redder and  for  several  in  Using  the  P h o t o m e t r y has apertures  from  11"  telescope,  Westerlund  red colors  disk  as o t h e r  i s too  made  by  as  as  and  measured  the  providing  OBV  reported negative i n that  presented  the  the  B-V  and  magnitude-aperture  been p u b l i s h e d by  280",  Hodge  and  Wall  et a l  for variability  al  showed  other observers i s l e s s  (1968),  plate  (1969), of  NGC  (1975),  Walker  who  and  in V  (1971),  by  measured  who  V  inch  that  the  to dust i n the  concluded  optical  Barnes  w i t h a 48  were due  morphological the  provided  suggested  1068 who  (1968) f o r 6  who  taken  p o s i t i o n s i n t h e d i s k , and  p e r i o d . Cannon e t  diagram  i n the f l u x ,  and  photographic  B  stars.  B bands.  Smith  0,  of l a t e type  (1968)  data they  b l u e f o r the g a l a x y ' s  in  out  size,  well  them and  cf the nucleus  r e g i o n , and  Surveys been  a  pointed  aperture  color  Vaucouleurs  relations  to  from  well  his  aperture s i z e s ,  also  isophotes  as  increasing  He  (that  nucleus.  available  f o r the U and  magnitude  radius).  i s composed  de  measurements  mag.  relation  that  with  in searching for v a r i a b i l i t y  color-aperture  very  Holmberg  l u m i n o s i t y i n the B band  scatter .1  had  the t o t a l  other Seyferts,  De  magnitudes  U-B  with  1068  results  the  became r e d d e r  NGC  nuclear  than  inside  underlying galaxy  comparison  that  measured  nucleus that  the  type. continuum  have  (1968) o v e r a 6 month  measured  photographic  B  63  magnitudes over  on  a three  year  8  plates  taken over  year p e r i o d ,  period.  sufficiently  In  each  and  Penston  study  existence  of  mag  v a r i a t i o n s i n t h e U,  rms  on  Lyutyi  (1973)  Seyfert  galaxies  "red"  the  a  later  optical  could on  with " b l u e "  nuclei, like In  on  NGC  1068,  paper,  brightness  time  scale  greatest studies  of  i n the  tens  basis  The  one  galaxies,  of  5-15  variations, the  l a g was  travel region,  from and  but  for  those  with  observations  the f a s t  of  the time r e g u i r e d  ratio  of  variation  15 d a y s .  amplitude of the  4 7  of  galaxy, on a  a time  the  of  the wedge scale  continuum  suggested  that  i o n i z a t i o n radiation to  t h e c e n t r a l s o u r c e t o t h e edge o f 10  He  was  on t h e b a s i s  v a r i a t i o n over  f o r the  a s i z e of  variability  through  of  and  occuring  depended  H°<  that  real,  a  the  component  with a l a g of about  thus derived  were  ,cyclic,  variation  also indicated  days r e p e a t i n g  that  that  time  filter  survey  f u r t h e r suggested  the  interference  of t h e i r  amplitude  and  Lyutyi's  and  with  c o r r e l a t e d with the a x i a l  luminosity.  .05  of  Zasov  1068  was  scale  a limit  (1977) i n d i c a t e d  variation that  the  flux.  components; one  of days.  Seyfert  not  d i d not.  and  He  one  establish  n u c l e i varied, while  years,  0 filter.  of s e v e r a l  the  v a r i a t i o n s i n NGC  s c a l e o f a few  to  V  however, L y u t y i  be s e p a r a t e d i n t o two  a time  and  a  f l u c t u a t i o n was  e t a l placed  B,  (1973)  e t a l (1974) over  errors  Penston  suggested  months, L y u t y i  the observed  above t h e p h o t o m e t r i c variability.  18  cm  the  f o r the  IK-forming H«c  region.  64  jdJL I/B  observations  Pacholcyzyk photometry by  for  Moroz and  2.1^  and  Wisniewski  NGC  1068.  Dibai  through  a  t h e s e o b s e r v a t i o n s was measurement, excess  as  T h e i r work was  (1968) who 20"  to  power  a  evidence  law  to  within  same, 3C  273,  and  and  o f NGC the  for variability  errors  of  and t h e y c o n f i r m e d t h e  I/E  W i s n i e s k i a t 2my/m  Kleinmann,  1068 form  the  1968,  studies from  and  of  Further  flux.  (Pacholcyzyk,  variation,  w i t h a t i m e s c a l e o f a few  limit  about 1 0  of  r e g i o n . He suggested explained  concluded  cm  Pacholcyzyk i n the  1970)  days,  presented  r a d i a t i o n of  NGC  at  confirmed  the  which  placed  1068  could  a  d i s t a n c e of  from  a  2.2/c  a model o f a s y n c h r o t r o n  source  in  outward.  8  cm  by  s o u r c e . I n s t e a d , he p r e s e n t e d decreases  10*  the  be  central  the f i e l d  be  which  the  which  region  that  a  emitting  i f t h e c e n t r a l , c o m p a c t s o u r c e were s u r r o u n d e d because i t r e g u i r e d  and  flux  t h a t t h e model o f Eees e t a l (1969)  not v a l i d  and  continuous  f o r t h e s i z e of the i n f r a r e d  t h a t the i n f r a r e d  d u s t c l o u d , was emitting  l s  the  . They a l s o  Styyv  i n the i n f r a r e d  monitoring  Kleinmann  Vf t o 25/f, w h i c h t h e y f i t  Weymann (1968) r e p o r t e d e v i d e n c e o f v a r i a t i o n 2.2/^.  and  the of  of  1.6//  c o l o r t h e y d e r i v e d from  Low,1970) t h e o b s e r v e r s r e p o r t e d distribution  at  The  (Low  energy  I/R  diaphragm.  that  papers  the f i r s t  s u p p o r t e d by a s t u d y  measured the f l u x  r e p o r t e d by P a c h o l c y z y k  I n two  (1967) p r e s e n t e d  65  Neugebauer 2.2/Y,and the  et  al  (1971)  1Q/i, and o b s e r v e d  smaller  measured  the  a d e p e n d e n c e on  wavelengths, i n d i c a t i n g  flux  a t 1.6^,  aperture  and extended  size  size  s o u r c e o f t h a t r a d i a t i o n , b u t no a p e r t u r e d e p e n d e n c e 10A  flux,  which  suggested  that t h i s radiation  10x  source,  distribution result  by  convolving  with t h e response  a  best  function,  Low  and B i e k e  (1971, a n d B i e k e a n d Low, o f t h e 10// f l u x  reported  an  apparent  decline  1972)  t h e same t i m e i n t e r v a l ,  1068  at  the  spectral  energy  was a b o u t  by  Fenston  wavelengths.  They  11/^ o v e r  They f o u n d  .Variability  that  was  e t a l (1974) who o b s e r v e d  a t 1.6/f, 2.2/1, and 3.4/f. They  these  at  b e t w e e n 8/f and 13*f c o u l d be  w i t h a power l a w o f t h e f o r m F ( V Y investigated  .5%. They  i n t h e 3.5// and 5/f f l u x .  o b s e r v e d no v a r i a t i o n .  distribution  presented  on o b s e r v a t i o n s  However, S t e i n e t a l ( 1 9 7 4 ) , m o n i t o r i n g t h e f l u x  also  source  comparing  based  made o v e r 3 y e a r s . The amount o f v a r i a t i o n  fitted  1" f o r  c o r r e s p o n d s t o a s i z e o f 100 pc f o r t h e 10_M s o u r c e .  evidence f o r v a r i a b i l i t y  the  of  t o t h e o b s e r v a t i o n s . A t t h e d i s t a n c e o f NGC 1068, ( 11  Mpc) t h i s  also  f o r the  f i t model and  f o r the  arose from a  p o i n t s o u r c e . B e c k l i n e t a l (1973) d e r i v e d a s i z e the  at  d i d not d e t e c t  NGC  variability  p o i n t e d o u t t h a t NGC 1068 h a d a  much s t e e p e r I/B spectrum, t h a n t y p e 1 S e y f e r t s .  Bieke  made  no b r i g h t n e s s  observations  changes l a r g e r Low  from  1.25 -10.6/{ and f o u n d  (1978)  t h a n 20X-  and Aumann  (1970) m e a s u r e d t h e s p e c t r u m  from  50-300/Y.  66  Their  results  and  a  indicated  steep  a peak i n t h e s p e c t r u m  decline  at  longer  a t around  wavelengths.  Subseguent  o b s e r v a t i o n s by H a r p e r e t a l (1972) and H a r p e r and Low failed by  t o confirm this detection.  T e l e s c o e t a l (1976) from  the spectrum  However, a i r b o r n e  28-320W,  indicated  a t 100/f, i n s u p p o r t o f t h e  70yy,  (1973)  photometry  a turnover i n  results  of  Low  and  and 1974b)  from  Aumann. The 2.2-27/C  o b s e r v a t i o n s o f Jameson e t a l (1974a indicated  s u g g e s t e d , based to  that  peak  source  was  in  the  on t h e s i m i l a r i t y  of a planetary  most l i k e l y reported  a  of  corroborated  I/E by  latter  observers  radiation.  Simon  and  measured  confirmed and  identified  studied  band p h o t o m e t r y .  strength that  by  the  radiation  from  feature. This et  they was  narrow  observers also reported  19/f, and  from  from  L e b o f s k y e t a l (1978), u s i n g  from o p t i c a l  distribution  (1975),  (1976)  further  a  determined  silicate  that  the  a higher e x c i t a t i o n  than  spectra.  J o n e s e t a l (1977) computed models t o energy  they  a t 10/f, which  a weak s i l i c a t e  of these features i n d i c a t e d  determined  peak  al  The l a t t e r  feature at  was t h e  by E i e k e and Low  by t h e s p e c t r o p h o t o m e t r y o f K l e i n m a n n  further  emission  as  They  o f NGC 1068  The Dyck  2.2-40/1 and d e t e c t e d a d i p i n t h e c o n t i n u u m tentatively  1&W.  dust r e r a d i a t i o n  o b s e r v a t i o n s a t 28/K and 33/(, b u t n o t o b s e r v e d (1975),. The  at  of the spectrum  nebula, that the  spectrum  3500A-300/C. T h e i r  f i t the  spectral  work i n d i c a t e d  that  67  the  observed  radiation  nucleus surrounded  could  be  modeled as a r i s i n g from  by a s p h e r i c a l d u s t c l o u d o f v i s u a l  d e p t h ~ 1 0 . They were u n a b l e t o f i t t h e r a d i a t i o n and  )r30/f,  suggested  a  optical  longward  of  t h a t t h i s r a d i a t i o n m i g h t be e m i t t e d by  r e g i o n s o u t s i d e t h e n u c l e u s . The d u s t  grains  used  in  their  model were a m i x t u r e o f s i l i c a t e and g r a p h i t e . Eecent Lebofsky  work  has  supported  the  model  e t a l (1978) f o u n d t h a t a power l a w  obscuring  cloud f i ttheir  source  et a l .  with  an  observations of the p o l a r i z a t i o n at  Their results indicated a different for  of Jones  polarization  angle  t h e 3.4/f p o l a r i z a t i o n t h a n t h a t g i v e n by K n a c k e and C a p p s  (1974).  In  decreased optical  addition,  they  with increasing observations.  found  that  the  a p e r t u r e s i z e , i n agreement w i t h t h e  They c o n c l u d e d  t h a t t h e n u c l e u s was an  intrinsically  polarized  nucleus  o n l y be o b s e r v a b l e i n t h e 1-5W  may  because a t nucleus  shorter  contribute  polarization  s o u r c e and s u g g e s t e d  wavelengths  the  significantly,  further that wavelength  stars  range,  surrounding  and a t l o n g e r  the  the  wavelengths  t h e d u s t e m i s s i o n becomes i m p o r t a n t . Thompson e t a l (1978) o b s e r v e d at  2.2/y[  dependence agreement  and on  determined  that  freguency,  with e a r l i e r  with  the spectrum  the continuum spectral  were  excited  NGC  1068  h a d a power l a w <=-2.6,  in  p h o t o m e t r i c r e s u l t s . They o b s e r v e d  the  m o l e c u l a r h y d r o g e n l i n e s a t X=2.04A/ and suggested  of  by s h o c k  index  X=2. 12/f,  f r o n t s produced  which  they  by r a d i a t i o n  68  from  t h e n u c l e u s i m p i n g i n g on d u s t c l o u d s o u t s i d e t h e n u c l e u s .  Carlson  and  molecular  Foltz  hydrogen  (1979)  source, using  Shields  and  all  Oke  photons  virtually  the  formation i n a region  continuum  photoionization  considered  the  radiation  (1975).  of carbon  with  Their  a l l the hydrogen  results  Badio observations  NGC  1068 was l i s t e d  i n t h e 3C c a t a l o g  observations  o f NGC 1068 made t o 1964 f r o m  (1967), from 154  study  Howard  i n this  and  wavelength  who d e t e c t e d a r a d i o  interplanetary  determined indicated absorb  by that  almost  i n the presence o f dust,  3C  next  50 pc from t h e  would  designated  The  of  i n t h e c l o u d s would be m o l e c u l a r .  fe)  271.  about field  i n the clouds  100A, and t h a t  possibility  as a r a d i o  Haran  (1964) 10 cm  region  list  to  800  the cm.  was by Cohen e t a l  source of diameter  scintillation  galaxy,  l e s s than  0»3  measurements a t 49, 70, and  cm. Bash  (1968) made i n t e r f e r o m e t r i c  He was a b l e t o a c c o u n t by m o d e l i n g components, about  f o r t h e observed  t h e source at that a  112 5..  interferometer  core  o b s e r v a t i o n s a t 11.1 cm.  of size  Kellermann  et  interference  wavelength less al  than (1970)  as c o n s i s t i n g  fringes o f two  1."5 and a h a l o o f s i z e used  a  two-element  w i t h a 10000 km b a s e l i n e t o measure t h e f l u x a t  69  13  cm.  Their  contains model  structure  the  Fomalont at  21  source  and cm  diameter  baseline  to the complexity  (1971) made  source  t o be  was  l e s s than  less et  along  than  al  (1972),  Heckman e t a l ratio  compared  and  the  supported  infrared  outer  ring  (Sandage,  1961), was  in  and  and 21.2  o f °<=-0. 75.  measurements b a s e l i n e . The  the  was  east-west  same  than Wilson from  (1977),  mass c o u l d be a  the  an  be in  scale  the o p t i c a l  of  by  and  by  unusually 1068 type.  i n t h e form  suggestion  H I may  photographs  confirmed  morphological  p r e s e n t e d a map the  1068  l u m i n o s i t y f o r NGC  observations  that  cm,  the  center,  of  larger  Bruyn  observations at index  most  visible  distribution De  the  Heckman e t a l a l s o that  to  spectrum.  H I i n e m i s s i o n i n NGC  o b s e r v e r s noted  missing  in  the  along  Steigerwald  latter  molecular hydrogen  indicating  that  source  baseline  T h i s o b s e r v a t i o n was  Eoberts  that  of the r a d i o  north-south  while  the  were u n a b l e  east-west  h y d r o g e n mass t o t o t a l  suggested  (1978).  an  the  to o t h e r g a l a x i e s o f  by  and  21",  cm.  ( 1 9 7 8 ) . The  of  they  interferometric  (1971) d e t e c t e d  by  that  15" .  o b s e r v a t i o n s a t 21  lewis  They  due  indicated  o f i'001 but  along a north-south  Allen  low  amplitudes  on a s c a l e  Moffet  of t h e  determined  from  fringe  of  which  is  Thompson  et a l  o f H I i n NGC  1068  a s s o c i a t e d with the  Hubble  length size  of  (1976)  presented  which t h e y  calculated  atlas the  of the  the  H  I  galaxy. continuum a  spectral  70  Observations Kuril'chik Brandie  1.35  et a l  and  Willis  and  Bridle  the  observations  They a l s o center,  cm.  two  source  cm,  Stull  3.8  cm  and  1.4  McCutcheon and observations  resolution  extending  to  discrete  coincides  with  Bruyn  and  (1978)  at  B r u y n and  Willis  (1968) i n t h a t  north  about  a  cm,  de  Gregory  bright  of the  19"  by  3.75  a p o i n t source  10"  source  at  cm,  of de  detected about  h a v e been made  (1971)  component model o f Bash  a  which  and The  at high  noted  wavelengths  (1974) a t  6 cm,  2.85  asymmetric  smaller  (1960) a t 3-5  (1974) a t  confirmed  at  their and  an  nucleus.  east  of  knot i n the  the  optical  image. Brandie variation years.  and  of  Bridle  NGC  1068  However, t h e  (1978) o v e r  (1974) after  Millimeter-wave al  (1968), who  reported  no  evidence  studies three levels by  flux  (Fogarty  periods  et  during  significantly  extrapolating  wavelengths.  NGC  for variability  i n observations  which t h e higher  the  Kellerman  energy and  flux  1068 from  over  1974) 3  mm  than  the  over flux  Pauliny-Toth  3.4  cm.  mm  observations  year.  curve  and a in  Further indicated  detected  flux,  by  over  a decrease  was  expected  distribution  a t 2.8  7 years,  4  Gregory  reported  at  one  for  f o r over  and  first  (1968) n o t e d  taken  a l , 1971,  the  evidence  variability  were  Fogarty  no  McCutcheon  indicated  detected  3 month p e r i o d . E p s t e i n and 3 mm  of  observations  Schorn e t  the  monitoring  observations  a 6 month p e r i o d  reported  at  estimated at  longer  (1971) r e p o r t e d  no  71  detection of  the  from  at t h i s  infrared  radio  X>  et  wavelengths  of  together.  the  flux  published  at  a  cm.  of the  to  at  f i t the further  1  mm.  which  a  from  energy  and  that  radio  no c h a n g e  the  spectrum  Most r e c e n t l y ,  of .6x10-2*  W m  Elias HZ-»  -2  measured t h e s p e c t r u m a t  f o rthe  noted  an u p t u r n i n  infrared  3.4  mm  distribution  they  but t h e  \>*\00/{  reported  limit  They a l s o  no d e t e c t i o n  as a r i s i n g  reported  an upper  curve  The I/B o b s e r v a t i o n s  e t a l d i d not d e t e c t  They  spectral  -10 cm r a n g e ,  explained  could  flux.  curve most  They  f o r the easily  a thermal source. Subseguently,  marginal  detection  again suggesting the p o s s i b i l i t y this  75  2 cm o v e r 2 y e a r s o f o b s e r v a t i o n .  (1978)  limit  observations at  t h a n a few p e r c e n t had been o b s e r v e d i n  9.5mm, and r e p o r t e d  100X  made  i n t h e spectrum  reguired  a l (1978) e s t a b l i s h e d  for  consideration  the sensitivity  They a l s o  to  Kellerman  spectrum  observations  at  and  wavelength.  a steep decline  observations  greater  flux  a s e x p e c t e d from  and p r e s e n t e d t h e c o n t i n u o u s e n e r g y d i s t r i b u t i o n  indicate  the  1068 a t 3 mm,  extrapolated  detectors 9,. 5 mm,  o f NGC  f o r t h e 3.4 mm  of variation  of the  be Jura  flux,  flux  at  wavelength. Submillimeter  (1977)  from  o b s e r v a t i o n s were made by H i l d e b r a n d e t a l  390-1 lOOyY.  spectrum  falls  results  of  Their  results  o f f s t e e p l y longward  Telesco  indicated  from  the  o f 100/f, i n s u p p o r t o f t h e  e t a l ( 1 9 7 6 ) . They d e t e r m i n e d  98% o f t h e power r a d i a t e d  that  NGC 1068 i s from  that  the  about  2 -1000/^  72  wavelength arising  region,  f r o m an o p t i c a l l y  (f)  dust cloud of s i z e a t l e a s t  e t a l (1971)  and  Olmer and  d e t e c t i o n i n attempts to observe  1068  u s i n g t h e OHUEU s a t e l l i t e .  possible Ariel  detection  I V Sky  the wavelength (1978)  fluxes  (4^r l e v e l )  Survey  Ultraviolet  al  thin  for  spectra  1068  150-3200 was  t h e IUE  this  o f NGC  satellite.  wavelength  lines,  reddening  7v<1.4.  Boksenberg  ~ 1.8,  correction  for  d e r i v e d from  the  UV  They  intensities  also which  derive is  a N/O  about  reddening  ratio  six  spectrum  was  continuum  correction  and is  from t h e e m i s s i o n l i n e  times  c o r r o b o r a t i n g t h e r e s u l t s o f S h i e l d s and  a  uncorrected  suggested t h a t the  after  et  continuum  i s much s m a l l e r t h a n t h a t i n t h e e m i s s i o n l i n e s ,  t h a t the t r u e s p e c t r a l index  over  which t h e y d e r i v e d  they found t h a t the r e s u l t i n g  power l a w . They t h e r e f o r e  the  kev.  presented  range from  reddening  using  a t low d i s p e r s i o n ,  They  the  Using  10-50  NGC  reported a  emission,  o b t a i n e d by  reddening.  a  5".  from  e t a l (1978)  X-ray  with s p e c t r a l index  not  as  (1976) r e p o r t e d  emission  I n s t r u m e n t , i n the range  range  using  Elvis  of  Murray  X-ray  power-law spectrum  jjS i f ]  b e s t modeled  H i ^ h enera_y o b s e r v a t i o n s  Kellogg no  and t h a t t h e s p e c t r u m was  the Oke  solar  (1975).  ratio,  73  It  is  useful  t o summarize the o b s e r v a t i o n a l s t u d i e s i n  terms of a d i s c r i p t i o n of the i n n e r 500  parsecs of the  In t h i s r e g i o n t h e r e are s e v e r a l clouds of gas to the emission  l i n e s . There are two  clouds f i l l region.  about .001  Within  the  of the t o t a l inner  100  which give r i s e  types of c l o u d s ,  i n t e r s p e r s e d , with d i f f e r e n t d e n s i t i e s and volume  galaxy.  probably  temperatures..These of  the  emitting  parsecs there i s an  optically  t h i c k dust c l o u d . In t h i s region there are c o l d , dense containing  molecular  ionization radiation energy  hydrogen, by dust  which  and by  is  clouds  s h i e l d e d from  photoicnization  of  the high  photons by carbon i n the c l o u d s . The c e n t r a l continuum  source of NGC  1068  i s nonthermal. Throughout the e n t i r e r e g i o n  there i s a s t e l l a r component as w e l l , which probably  dominates  the .continuum r a d i a t i o n at v i s u a l or s h o r t e r wavelengths. infrared in  the  radiation central  nonthermal  appears t c a r i s e from r e r a d i a t i o n by  regions.  compact  component  the o p t i c a l c e n t e r , and The 8.  The  radio  radiation  The dust  includes  a  i n the c e n t e r , c o i n c i d e n t with  an extended component.  o b s e r v a t i o n a l elements of NGC  1068  are given i n Table  74  Table 8 Elements Of NGC  B.A. Dec  1068  2"40ri  (1950)  -0° 14'  (1950)  1, b  172^09, 51.*94  L, B  304:9, -25:8 (B) SA  Type  Apparent  9.7  magnitude  0.66  (B-V)  Mean a x i s r a t i o  0.80  Face-on  4l9  diameter  Corrected  The  +1094 km/s  velocity  2. Photometric  was  b  •1080 km/s  Velocity  Color  (rs)  Calibration  photometric  c a l i b r a t i o n f o r the V image of  achieved through comparing simulated a p e r t u r e  with p u b l i s h e d photometry. The p o s s i b i l i t y  of  NGC  1068  intensities  variations  in  the n u c l e a r b r i g h t n e s s of t h i s galaxy has been i n v e s t i g a t e d by a but  number  of o b s e r v e r s , as d i s c u s s e d i n the p r e v i o u s s e c t i o n ,  with no c o n c l u s i v e r e s u l t s . However, an examination  published larger  photometry  than  the  of the  (Figure 19) shows a good d e a l of s c a t t e r ,  formal  uncertainty  estimated  in  the  75  observations, result 1.  lyutyi  (1977)  of v a r i a b i l i t y  However,  of the  Penston  et  variabilbity  based  observations  through the  no  greater  than  difficulty  on  the  with  this  especially  on  the  would  a  source  be  nucleus,  al  the  rms  considers  find  t h a t the  same a p e r t u r e e r r o r i n the is  that  r a p i d time of  no  rms over  a  the  scatter  to  calibrate  section  evidence of  for their  photometry.  nucleus  rms  a  2.year p e r i o d i s  published  i f  in  scatter  s c a l e suggested  the  s c a t t e r t o be  as d i s c u s s e d  (1974)  fact  the  The  i s variable,  by  Lyutyi,  in  the  this  published  magnitudes. Therefore, there V-v  was  i n attempting  considerable  obtained  addition,  the  published  for  any  one  set  of  the  CCD  data  apertures  and  the  colors  B'V  aperture data  size.  be  discrepant (Figure  of  aperture published  tended  attempting  20a)  the  form  the  CCD  agree  data  instrumental fitting  standard  magnitudes, the  were ^=25.47,^?=-.7692, w i t h  the  larger  (see T a b l e  9)  with  the  CCD  seen i n F i g u r e  20b.  with  of  an  expression  of  (7)  V magnitude, values  In  trend  V = v / + "< + y J c V - r J where V d e n o t e s t h e  for  systematic  be  constant  photometry,  photometry  can  image,  photometry.  apertures  showed no  However, t h e s i m u l a t e d  to c a l i b r a t e  to  at smaller  shows a v - r c o l o r g r a d i e n t , a s  In  CCD  d i f f e r e n c e i n the c a l i b r a t i o n  from  calibration  the  and  v  and  obtained  by  an  (sum  error  r  the  least-sguares of  sguares)  76  cf  .0946. Because,  discrepant  as  at  noted  earlier,  smaller  guestion  of  wavelengths, variability  on  Accordingly, luminosity enough  V-v  variable  of  necessary  photometry  the  to  the  (1968)  as  was  was  a  Thus  of  both  annulus color  as  effects. for  in  Eguation  the  that 7  the  d a t a was  V  results  data  Reference of  de  and  NGC  of t h e l e a s t  and  4 i s the data of Smith  is  of  et  al  the  large de  resulted  in a  the  of  a  published affect  took  the  account  inside  each  a l o n g w i t h t h e v^-r compared from  through  the p u b l i s h e d  sguares f i t t i n g  are given  of  and  of Walker  Vaucouleurs  1566.  by  must  were  derived  of  by c o m p a r i n g  magnitude  determined,  magnitude  2 i s that  Penston  for  calibration  these  Reference that  effect  assumption  gradient  instrumental  T a b l e 9. E e f e r e n c e 1 i s t h e d a t a  (1968), the  The CCD  the  f i t to  so the a d o p t e d  annulus,  to  p h o t o m e t r y . The in  well,  optical  measured  the  better  p h o t o m e t r y . However, t h e v - r c o l o r calibration  at  9"x7'. T h i s c a l i b r a t i o n  allowed  more  expected i f  with i n n e r diameter  region,  o f 24.97, w i t h C~=. 037. nucleus  done  calibrated  nuclear  as  nucleus  consider  successive annuli,  exclude  is  b e c a u s e t h e r e i s c o n t r o v e r s y on  the c a l i b r a t i o n , the  Vaucouleurs mean  is  inside  to  and  variability  i t  calibration  a p e r t u r e s , which would be  t h e n u c l e u s were v a r i a b l e , the  the  Westerlund  (1968), E e f e r e n c e 3 i s  de  et a l  Wall  Vaucouleurs (1972), and  ( 1 9 7 4 ) . The  24"  (1968),  Reference  aperture of  5  this  77  l a t t e r data markedly For  the  aperture data  was n o t u s e d i n t h e c a l i b r a t i o n ,  because  d i s c r e p a n t i n comparison with the other other  existing  photometry,  there  i t was  measurements.  were n o t e n o u g h  9" t o make c o m p a r i s o n w i t h t h e  s i z e s l a r g e r than  CCD  useful. Two  measurements  (Pacholcyzyk However,  and  since  of  E  magnitudes  Wisniewski,  each  1967,  observation  have been p u b l i s h e d  0 Dell ,  et  a l , 1978).  i n c l u d e d o n l y one a p e r t u r e  s i z e , i t i s n o t p o s s i b l e t o c a l i b r a t e t h e CCD E i m a g e f r o m t h e p u b l i s h e d p h o t o m e t r y , due t o t h e a p p a r e n t of the nucleus. was  derived  not  change  the  for this little  nucleus  Pacholcyzyk  magnitude  and  varies.  and  i s  does some  e t a l (1974),  change i n c o l o r w i t h b r i g h t n e s s  variations  studied.  Wisniewski  give  V-E=.747  for a  15"  O ' D e l l e t a l g i v e V-B=.75 f o r an 18" a p e r t u r e .  to the calibration f o r the  given  15" a p e r t u r e  in  Table  f o r the  CCD  image  9,  the  CCD  V  i s 11.11, u s i n g t h e measured  i n s t r u m e n t a l v - r c o l o r o f . 9 2 . F o r V-E=.747, magnitude  There  i n t h e data o f Penston  f o r t h e S e y f e r t g a l a x i e s they  According  image  by making t h e a s s u m p t i o n t h a t t h e V-B c o l o r  justification  aperture,  variability  T h e r e f o r e , a rough c a l i b r a t i o n o f t h e B  while  who i n d i c a t e  directly  i s  10.36.  the The  standard  B  corresponding  instrumental  r m a g n i t u d e i s - 1 4 . 7 8 . F o r t h e 18" a p e r t u r e ,  instrumental  v magnitude i s -14.06, t h e r magnitude i s -14.95,  and  the corresponding  V magnitude, from t h e c a l i b r a t i o n  the  given  78  Table 9 Photometric  Ap diam 12"  20"  V 11.05  10.56  Calibration  Bef  CCD v  1  -13.59  1  -14. 18  Of The V Image Of NGC  v^-r  1  -14.80  .74  11"  11.03  2  -13.49  .94  2  -14.  CCD v  V-r  12" -20"  11.66  -13.22  .73  12"-40"  10. 55  -14.37  .6/  11-17  11.97  -12.92  .71  .87  10.02  10.65  V  .97  40"  17"  Annulus  1068  .90 j  10.94  -13.97  .71  16"-3i:'5 11.27  -13.77  .7k  -13.85  .61  11"-28" 28"  10. 23  2  -14.51  .83  ie: 2  10.8  3  -13.94  .91  31.'5  10.26  3  -14.61  .81 16-33"  33"  10.22  3  -14.65  .81 . u  11.17  79  Ap diam 17"  26"  34"  V  Bef  10.94  10.53  4  4  4  10.3  CCD V - -14  V  Annulus  v-r  CCD v  v-r  . 9  -14.44  -14.68  17"-26'  11.74  -13.25  •V  17"-34"  11.18  ^13.84  .67  .85  I  .79  I  15"  10.82  5  -13.85  .92 |  I 15"-24" 24"  30"  45"  10.54  10.25  10.01  5  5  5  -14.36  -14.57  -14.88  Calibration:  12. 15  -13.3  .11  1 1  .86  - .82  15"-30"  11.22  ^13.78  .7/  15 "-45"  10.71  -14.35  .4*  j  ,.68  V = v + 2 5 . 0 9 - . 14064 ( v - r )  '  •30  ?~5 m.  •* If  A  /a.  I.O  II toe.  I-ifareitrLiKe  l-J  <-f  IT  IS  I.J  J.O  Ot/tHereK.)  F i g u r e 1?: V magnitude-aperture r e l a t i o n f o r NGC 1068, d e r i v e d from the p u b l i s h e d photometry. A p e r t u r e d i a m e t e r s a r e i n arcseconds. The v a l u e s determined by the v a r i o u s o b s e r v e r s may be d i s t i n g u i s h e d u s i n g the f o l l o w i n g key: •=Walker (1968) o=Westerlund and W a l l (1968) •=de V a u c o u l e u r s and de Vaucouleurs *=Smith e t a l (1972) A=Penston e t a l (1974)  (1968)  .7  -T  .1  i.o  LOG.  1.1  ri.  7J  (fiPeATUHE Dm/IE  7*  7*,  Ti  71  Ti  Ti  f£«)  F i g u r e 20: (a) v - r c o l o r - a p e r t u r e r e l a t i o n f o r NGC 1068, obtained from the CCD o b s e r v a t i o n s . A p e r t u r e diameter i s i n arcseconds. (b) (B-V) c o l o r - a p e r t u r e r e l a t i o n f o r NGC 1068. The from the p u b l i s h e d photometry l i s t e d i n F i g u r e 19.  points  are  82  in  Table  V-B  of  the  18"  9,  .75.  the  the  CCD  t.01  calibration t h e CCD  +.14  of  the  errors  mag  sources i n the  c e n t e r i n g the  error  However, t h e  section  tend  nucleus.  In any  r e s o l v e d , the  light  to support case,  best  published  p h o t o m e t r y can  used  to  by  V a u c o u l e u r s and  discussed  which  might  the be  V  the error  in  the  is  so  the  Appendix.  the  image, Seyfert  toward  presented  in  the this  of v a r i a b i l i t y  of  the  of  is  not  variability  one  which  The  discrepancy  profile,  deVaucouleurs  of  concentrated  significant  to  difficulty  o f the  photometry  guesticn  galaxy.  explain  the  brightest part  is  subject  also  particularly  possibility  luminosity  f u r t h e r i n the  in  as t h e  also  the  cali-bration of  f o r the  photometry. course  since the  regions  d e r i v e the  the  photometry  mag  same o r d e r  arguments p r e v i o u s l y  central  de  on  important the  +.04  is  uncertainty  i s of  observations,  very  since  published  aperture  are  the  from  i s s u b s t a n t i a l l y b e t t e r than  photometry of  in  image. The  V image i s o f t h e  published  center.  apertures  f o r the B  The  galaxies,  B-r=25.14, and  observations,  V photometry. This  be  measured  adopted c a l i b r a t i o n  s c a t t e r i n the  which c a n  aperture,  the  the  f o r the  discrepancy  E=10.15 f r o m  B-r=25.1, s o  mag  other  15"  outermost simulated  image, and  in  which i m p l i e s  Then from t h e  aperture,  For for  i s 10.9,  i f the i n the  (1974).  excludes in  photometry  the the is  manner o u t l i n e d This  point  is  83  Figure reddening in  this  the  of  21  shows  t h e COMTAL v - r  the  galaxy  towards the  p h o t o g r a p h . Of  regions  of  enhanced  elogated  region  regions,  however, t h e  toward 1959,  P.A.  of  along  30".  the  .of  the  features  the  red  the  tend 45 .  an  this  1068. is  The  evident  fact  that  to l i e i n In  an  the  inner  gradually  twists  (cf.,Burbidge  et a l ,  s  investigators  along  is  of e l o n g a t i o n  have n o t e d  mentioned  interest intensity  direction  galaxy  central regions  major a x i s , P.A.  Other  E e r t o l a , 1968)  regions  particular  image f o r NGC  asymmetry  in  direction.  The s i g n i f i c a n c e  here w i l l  be  discussed  the  in  nuclear  the  next  section.  3.  Luminosity  The Figure 26.  Profiles  contour 22,  map  and  region  of  obviously  present  addition,  the  southeast For  NGC  obscuration,  as  1068  brightness  visual  innermost  apparent  galaxy  visual from  these  within falls  14" off  t h a n on  be  also  the  clearly  seen i n F i g u r e  1068  i s shown i n  image i s shown i n  image, i n a d d i t i o n to  contours can  image o f NGC  figures  i s a s y m m e t r i c . The  to at l e a s t  s i d e of the the  red  t h a t f o r the  I t i s immediately  inner  the  f o r the  26  from much  that  spiral the  these  the  arms  are  center.  In  faster  opposite  Figure  on  the  side. asymmetries,  show  the  presence  and  in  the  of  COMTAL  84  picture Figure 5"  of 27.  For  of the  of the  21)  As  inner  the  regions  as  a  This  a region  guite  contours  appears  in  o f enhanced  of  profiles  visual  marked e l o n g a t i o n  also  result  luminosity  of the  r e d image, t h e  image show a  galaxy.  (Figure  are  tbe  the  of the  complicated,  and  as c a n  visual  he  luminosity  profiles  methods:  described  in  Chapter the  method  2 f o r NGC  contours,  f r o m the two  315". rapid  the  simulated  profiles  running  1566,  from These  aperture from  center  last  fall-off  uses the  plotting  of the  two  in brightness  on  images o f  NGC  derived  23  and  and  of  images,  P.A.  and  a  and line  at  effect side  in  derived  along  southeast  three  radius  intensity 135°  28.  used  Appendix, CCD  the 1068  from  1,  i l l u s t r a t e the the  image  here,  of the  the  axis  descussed  i n the  image a t  profiles  v-r  eguivalent  photometry  inner  major  COMTAL  Chapter  method d i s c u s s e d  derived the  which  the  seen i n F i g u r e s  T h e s e f i g u r e s show t h e the  along  the  emissicn.  asymmetries red  outside  the  red  i m a g e , shown i n  P.A. of  the  of  the  i t is  not  image  by  from  the  galaxy. For possible  NGC  then,  to approximately  generating luminosity the  average  For  the  the  1068  a  reproduce  two-dimensional,  profiles.  Bather, the  p r o p e r t i e s of  a n a l y s i s of these  contour  i n contrast to  maps w i l l  be  the  the  NCG  observed  axisymmetric luminosity  surface  images, the used, s i n c e  1566,  model  profile  brightness  represents  distribution.  profiles  derived  this  of p r o f i l e  type  from is  85  independent of e l l i p t i c i t y . is  affected  by t h e  a r m s . At r a d i i profiles least  are  11'  (r =1.82)  the  y,  change i n c o n t o u r s h a p e due  less  than  this,  well described  by  i t  can  be  t o the  seen  a deVaucouleurs r  profile  that  law,  ,/V  spiral the  over  at  6''. As  mentioned  in  C h a p t e r 1, an H°c image o f NGC  also obtained  w i t h t h e CCD.  this  For  image.  this  outer  the outer  regions  Figure  31 i s a COMTAL  picture,  l o g r i t h m i c s c a l e i n order the  Beyond  could  contour t o the  the  data  was  1068  was  picture  converted  of to  t o r e d u c e t h e d y n a m i c r a n g e so be s e e n . The  that  change i n i n t e n s i t y  inner contour i s a  factor  a  of  from about  90. Onfortunately,  the  signal-to-noise ratio this,  several  discerned. very  contour and The  shifting the  of  the the  i n the  center  of the  p l o t o f t h i s i m a g e . The  and the  galaxy,  corresponding t h a t the  for  has outer  a  rather  contour).  H^-emitting  with  red  the  were  H°< i m a g e so t h a t t h e the  f e a t u r e on  Figure  the  major  32  can  be  emission  is  shows  the  i n n e r c o n t o u r s agree i n shape  c e n t r a l c o n t o u r s of  images  along  galaxy.  low Despite  region  most n o t i c e a b l e f e a t u r e i s t h a t t h e  inclination H<  (-8  features  The  intense  data  the  geometrically knot i n the axis,  red  image.  registered south  coincided  region  of  with  the  r e d i m a g e . From t h i s i t was  c e n t r a l c o n t o u r s o f t h e two  A s e c o n d f e a t u r e t o be n o t e d  images a l s o  i n the  by  found  coincided.  image i s t h a t  the  86  elongation  along tbe  seems  to  be  along  the  major a x i s o b s e r v e d  i n t h e r e d image  p r e s e n t h e r e . T h i s f e a t u r e i s somewhat  southwest  side  columns  of  pixels  in  accounts  f o r the abrupt  because  that  there  region  truncation  were  also  obscured  several  o f the CCD  bad  a r r a y , which  o f t h e image on  the  south  side. A in  final  f e a t u r e of the  the o p p o s i t e sense  region of these most If  rapidly  to the  latter  (P.A,  in  135')  r e g i o n o f NGC  the  1068  r e d and  for  this  from  in  i s due  galaxy,  continuum  to  component. The  they  2.11x10-**  H*  flux  to the red  reported but  t o be  as n o t e d  by  dust  would  indicate  that  this  and  1068  dust. ,  includes  of  light  s  - 4  ,  Shields  and  a 7"  Shields  (cf E i l e k and  Oke  Oke  and  correct nuclear  according  ( 1 9 7 5 ) . The  to  total  derived  1.5x10-*° e r g s c m  from s  - 2  aperture  IK  flux  e t a l , 1973, Koski  has  _ 1  .  is  c o n t r i b u t i o n of the  The  by  to  the  emission i n that  14SJ.  significant  necessary  aperture  so t h e t o t a l  i s about  variable  a  calibrated  i s approximately  2  off  of  image was  measure f o r the HX  e r g s cm-  falls  presence  determine  i n the red bandpass through measurements  the  the  to  flux  flux  gas  attempt  spectrophotometry  The  to  t h e E°< e m i s s i o n , i t was  the  their  v i s u a l image, i n t h a t  this  c o n t a i n s both  order  asymmetric  i s a r e g i o n o f enhanced IK e m i s s i o n .  S i n c e t h e r e d image o f NGC contribution  it is  images where t h e b r i g h t n e s s  the b r i g h t n e s s f a l l - o f f  obscuration  IK image i s t h a t  H<*  been  Lyutyi,  1977),  (1978) t h e  total  87  strength  of the  reported  I K * [N I l [ b l e n d  v a r i a t i o n may  deconvolving.the the  CCD  ignorable  in  the  intensity was  strongly for r  a  w i t h i n the  to the  covered  disk  the  photometry  the  s i n c e the  p l o t of  i n Table  disk  the  1068.  An  the  variation  is  the  diameter r e g i o n of the  HX  i n s i d e the  the  map The  to  scaled  corresponding  then subtracted resulting  of Figure  luminosity  22,  24,  from  image  was  except l e s s  profile  s p i r a l a r m s , and  CCD  derived  plotted  against  to the  limited  possible to  observations.  derived  from  a t t e m p t was CCD  observations  was  derived  the  from  in this  the  Appendix  published  to  this  V  disk  perform  an  b u l g e components  used i n C h a p t e r 2 f o r achieved  determine  The  made t o use  d e r i v e t h e d i s k and  c o n v e r g e n c e was  profiles  error  10.  profile  with  procedure  for  so t h a t  image, i t i s not  from  f o r NGC  no  was  H°c image was  center.  V i m a g e , s u c h as  However,  image  contour  t h e CCD  p r o f i l e together iterative  H°<  e f f e c t of the  by  for  used  [N i f ] l i n e s t h e  image i s shown i n F i g u r e  profile  describes  for  the  tabulated  technigues  possible  i n n e r 7"  contour  to  red-H*  Due area  CCD  peaked i n t h e  the , and  by  the  approximation.  r e d i m a g e . The  similar  so t h a t  c a s e , s i n c e the f i l t e r  calibration  the  r e d i m a g e . The  very  different  14% o f t h e t o t a l i n t e n s i t y  r e g i o n of the the  to  a l s o i n c l u d e s the  in a first  Accordingly,  image  due  l i n e s . I n any  observations  introduced  total  be  a g r e e s w i t h i n 5%,  NGC  process.  photometry  1566. Indeed,  assume  a  88  circularly  symmetric  s t r u c t u r e f o r t h e observed  galaxy,  i t i s not convincing  profile  of Figure  made  to  29 would  combine  photometry  with  photometry  of  the that  NGC  disk  a radius  model d e r i v e d  star-like  than  simulated  aperture  of  failed  photometry  derived  the l i g h t  also  procedure.  20% o f t h e t o t a l  the disk  also  published  from t h e p u b l i s h e d  50%  which  component  profile  the  complication  profile  o f NGC  light  for  inside  f o r NGC  1566  inside inside  error  this  which  were  profiles  used  Chapter  2 f o r NGC  the  observations the seeing  o f NGC  profile  c o n t r i b u t i o n o f the  arose there  these  models  1566 o b s e r v a t i o n s  the  i n the visual  introduced  1068 i s t h a t  the bulge  NGC  of  in  ignoring  unacceptable.  Therefore  The  brightness  obscured  the r e l a t i v e  a v a i l a b l e f o r the night  in  the  mostly  f o r r<11" i s n o t  further  luminosity  i s  further diminish  d i s k component. T h e r e f o r e  in  the  was  the  image. T h i s a t t e m p t  And f o r t h e r e d i m a g e ,  nucleus,  i m a g e , would  A  from  from  with the  I n t h e c e n t r a l r e g i o n s , t h e d i s k c o n t r i b u t i o n would be  even s m a l l e r .  this  derived  c o n t r i b u t e about  more  data  solution i n the i t e r a t i v e  o f 18". By c o n t r a s t ,  contributes radius.  profile  t h e CCD v i s u a l  1068 would  this  be m e a n i n g f u l . An a t t e m p t  derived  to produce a converging The  that combining  image o f t h e  in  analyzing the  was  no  observations  convolved  with  seeing  were made. the  seeing  1566 ( F i g u r e s 8 and 16) .  were made on t h e s u b s e g u e n t n i g h t t o  1068. As a t e s t  o f the e f f e c t  would h a v e on t h e c o n v o l u t i o n ,  a change the bulge  89  model f o r t h e Gaussian the  red  seeing  profile  convolved  determined 1566.  image  bulge  differed  by c o n v o l u t i o n  does  convolution, actual  The bulge  not  fit  t o the observations  region  of  luminosity  i s  describes NGC  Within  very  1566.  an  used f o r NGC  of  the  seeing  results  of  the  approximation  to  the  i s shown i n F i g u r e  had  this  a  surface  -/V.903  24. The  brightness  provided  subtracted  relative  the  the  a good  from  the  be  described  25.  by  a  o f t h e ferm  slope  (io) of  Eguation  distribution  nucleus  to the bulge,  diameter  can  -f ,7?V^  to  However,  c o n t r i b u t e s about  profile  was  profile  distribution  close  8,5  bulge  profile  the s u r f a c e b r i g h t n e s s  brighter,  that  and t h e r e s i d u a l s a r e p l o t t e d i n F i g u r e  JUCK. which  3.58 from  i n t h e i n n e r 11".  bulge  profile,  Gaussian  pure  profile for  profile  the  a reasonable  seen, the convolved  convolved  inner  than  a  ( i n magnitudes) o f t h e form  can  initial  with  shape  affect  convolution,  as  The  exact  of t h e c o n v o l u t i o n  model, b e f o r e  be  less  the seeing  the  that  convolved  i s used.  result  distribution  of  with  by  strongly  provided  profile  also  cn=0.9. The r e s u l t i n g  with  Thus i t a p p e a r s t h a t  profile  The  was  of  than i s  aperture,  15% o f t h e t o t a l  the  of  NGC  that  the  nucleus  1068  i s much  of  nucleus  red l i g h t  3, w h i c h  NGC o f NGC  (including  1566. 1068 H°<) ,  90  as  compared t o 5% f o r t h e n u c l e u s The  manner.  visual  image  The l u m i n o s i t y  plotted  vs  r'"* i n  deVaucouleurs convolution  law of  of  profile  Figure for  the  NGC  o f NGC 1566. 1068 was a n a l y z e d  is  29.  listed  This  4.'4<r<11".  bulge  Figure  16 i s a l s o p l o t t e d  before  convolution,  model in  Table  profile The  with  Figure  was d e s c r i b e d  in  i n t h e same and  i s fitted  results  The  the  profile of  bulge  by a l u m i n o s i t y  to a  of  the seeing  29.  11  model,  distribution  of the form  As  before,  initial  profile,  It  the convolved  profile  and t h e r e s i d u a l s a r e p l o t t e d i n  i s not possible t o f i t this  luminosity  distribution.  consideration  of  the  residual profile  This  is  asymmetry  (Figure 26), apparently  dust.  result  at  too f a i n t visual  that  the  point  wavelengths.  renders  t o be d i s t i n g u i s h e d from  the  wavelengths l e s s than that  obscuration  wavelengths.  suggested  due  However, nucleus  could  component  in  of the  obscuration  nucleus  of  Lebofsky  derived  be  NGC stars  et  observed here  by  et a l  the surrounding  not  can  30.  to a Gaussian  of Lebofsky  the  whereas  1^, t h e p r o f i l e s  source  Figure  surprising  to  amplifies the suggestion  (1978) t h a t t h e d u s t 1068  not  from t h e  of the inner contours  v i s u a l image This  was s u b t r a c t e d  al at  indicate  be d e t e r m i n e d  at red  91  F i g u r e 21: COMTAL v - r map f o r NGC 1068. The i n t e n s i t y s c a l e i s c o l o r coded so t h a t the r e d d e s t a r e a s are t h o s e w i t h the l a r g e s t v - r , and the w h i t e a r e a s a r e those w i t h the s m a l l e s t v - r .  '93.  20-0 -J  30-0 1  tH.D 1  50.0 1  60.0 1  70.0 I  _i  Figure 22: Isophotal contours for the red image of NGC  80.0 I  1068.  90.0 I  !M I  0  not  J_5  Table JO Surface r  B r i g h t n e s s D i s t r i b u t i o n Of The  (arcsec) 0.50 0.77 1.00 1.2 2 1.44 1.67 1.93 2.28 2.55 2.92 3.39 3.97 4.57 5.25 6.01 6.73 7.57 8.49 9.56 10.88 12.40 13.38 14.34 15.20 16.00 16.77 17.46  B Imaqe Of NGC (mag/o- )  14. 19 14.35 14.51 14.67 14.83 14.99 15.16 15.32 15.48 15.64 15.80 16.97 16. 13 16. 29 16.45 16.64 16.77 17.94 17. 10 17.26 17.42 17.58 17.75 17.91 18.07 18. 23 18.39  1068  9V  4 4 4 4 4  4  i  4  rs!"  4 * H  X .  u  *  "  X H  4 •  X  csi-l  V  * M  »  ft "  ,  0 0  3.0  ,  6.0  1  9.0  RflD  , I 12.0  I  15.0  18.0  (flRCSEC)  F i g u r e 23: L u m i n o s i t y p r o f i l e s f o r the r e d image of NGC 1068. The v a r i o u s p r o f i l e s are as f o l l o w s : * = p r o f i l e d e r i v e d from the contours o f F i g u r e 22. = p r o f i l e d e r i v e d from the s i m u l a t e d a p e r t u r e photometry * = p r o f i l e a l o n g P.A.135* (northwest along minor a x i s ) * = p r o f i l e a l o n g P.A.315° ( s o u t h e a s t along minor a x i s ) x  <fS  <y.  F i g u r e 24: L u m i n o s i t y p r o f i l e f o r the red-H< image o f NGC 1068, d e r i v e d from the v a l u e s o f T a b l e 10. The s t r a i g h t l i n e r e p r e s e n t s the observed deVaucouleurs law, d e s c r i b e d by the e q u a t i o n  M*.  - ft-Vf  The dots (») a r e the observed convolved b u l g e model.  3.237r''i  p r o f i l e , and the c r o s s e s (*) r e p r e s e n t the  O  —n  0.0  i  i  1.0  2.0  i  F i g u r e 25: R e s i d u a l n u c l e u s (H* emission subtracted). by the e q u a t i o n M903  t  3.0 RAD  i 4.0 (ARCSEC)  i 5.0  o f the r e d image o f NGC 1068 The s t r a i g h t l i n e i s d e s c r i b e d .7?^r^  F i g u r e 26: I s o p h o t a l contours f o r the v i s u a l image of NGC v a l u e s and c o r r e s p o n d i n g r a d i i are g i v e n i n T a b l e 11.  1068.  The  contour  Table Surface r  jn  B r i g h t n e s s D i s t r i b u t i o n Of The (arcsec)  0.98 1.55 2. (15 2.66 3.05 3.41 3.77 4.16 4.57 5.06 5.62 6.26 6.92 7.63 8.46 9.40 10.49 11.69 12.75 13.66 14.49 15.26 15.91 16.67 17.31  V Image Of NGC (mag/a" ) 15.63 15.78 15.93 16.08 16.22 16.36 16.50 16.63 16.77 16.90 17.04 17. 17 17.31 17.44 17.57 17.71 17.84 17.97 18. 10 18. 23 18.37 18.50 18.63 18.76 18.90  1068  99  F i g u r e 27: COMTAL p i c t u r e o f the v i s u a l image o f NGC 1068, m a g n i f i e d t w i c e to show o n l y the i n n e r r e g i o n s . The h i g h e s t i n t e n s i t y a r e a s are w h i t e , and the l e a s t i n t e n s i t y areas a r e r e d .  IOO  If H  01  ' J<  M •  X  ID O H  0.0  ~~r— 3.0  »  I—  6.0  9.0  RAD  12.0  CflRCSEC)  )5.0  F i g u r e 28: L u m i n o s i t y p r o f i l e s f o r t h e v i s u a l image o f NGC The v a r i o u s p r o f i l e s a r e marked as i n F i g u r e 23.  16.0  1068.  101  at  F i g u r e 29: l u m i n o s i t y p r o f i l e f o r the v i s u a l image o f NGC 1068, d e r i v e d from the v a l u e s o f T a b l e 11. The s t r a i g h t l i n e d e s c r i b e s the observed deVaucouleurs law. The dots (•) a r e the observed p r o f i l e , and the c r o s s e s (*) are the convolved bulge model.  lox  r-'.  .—o LU  to CJ QC  az  \ „  CD • C E -I 0 3  oo-l  0.0  1.0  2.0  3.0 RRD  4.0  5.0  (flRCSEC)  F i g u r e 30: R e s i d u a l s f o r the v i s u a l image o f NGC s u b t r a c t i n g the c o n v o l v e d b u l g e .  1068,  after  103  F i g u r e 31: COMTAL p i c t u r e o f the H<K image o f NGC 1068; d a t a c o n v e r t e d to l o g ( i n t e n s i t y ) v a l u e s . White a r e a s a r e the h i g h e s t i n t e n s i t y , b l u e - r e d a r e a s a r e the l e a s t i n t e n s i t y a r e a s .  105  Um. D i s c u s s i o n  data  The same c a v e a t  attached  also applies to  NGC 1068:  extend  to  about  18"  c o n c l u s i o n s drawn. any  information  CCD d a t a . bright  It  the  a n a l y s i s of  fact  As mentioned, i t  about  spiral  that the  adds a good d e a l o f  the  is  not  arms have on t h e  obviously affect  the  profile  for  not  the  Within  too  these l i m i t a t i o n s ,  comparison of images.  profile  the  bulge  Eguations  9  r e g i o n than i n the  the  bulge  i n s i d e a 10"  outer  aperture  2.22,  much r e d d e r t h a n  the  of  point  13.32,  the  determined visual  source i s since  the  NGC  the  to  derive from  except  r>11". the  the  the very  to  say  However,  outer  disk  the  would  possible to of  is  the the  region.  p r o v i d e some  red  and  bulge i s redder The V magnitude  1 3 . 1 5 , and t h e NGC 1566.  but  no  visual  V  V-E color  in of is  The E m a g n i t u d e  magnitude  s o u r c e component i s  not  can  be  seen  at  wavelengths.  bar-like in  is  b u l g e of  point  The c o n t o u r p l o t s for  it  and 11 show t h a t  inner  NGC 1068  only  greatly.  component  the  1566  profiles  p o s s i b l e to  profile,  in s e c t i o n 3 demonstrates that bulge  NGC  what i n f l u e n c e t h e  discussion affect  the  uncertainty  d i s k component o f  a l s o c a n n o t be d e t e r m i n e d  inner  that they  to the  1068  (Figure  elongation  then  21)  the  If  this  fact  21 and 25)  show t h a t  along the  v i s u a l image.  component,  (Figures  major  the  axis,  and t h e red  v-r  image e x h i b i t s  which i s  not  represents a d i s t i n c t  that  it  is  present  image  in  the  a  present  structural red  image  106  a f t e r the it  emission  has been subtracted  out  indicates  c o n s i s t s of red s t a r s r a t h e r than gas. Since  the  point  source  component  feature  i s not so dependent on the shape of the bulge region.  the  1068 i s much  than t h a t of NGC  i n the i n n e r  1566,  of NGC  stronger  33  Figure  determination  shows  the  of  For  the the  this  profile  observed  convolved r e s i d u a l s f o r the v i s u a l and red images of NGC  so  that  minus 1068.  red image, cr=. 004, and f o r the v i s u a l image, cr=.007, nuclear  component  of  the  red  image  is  very  well-determined. A  final  point t o a r i s e from the a n a l y s i s o f t h i s data i s  t h a t the emission  l i n e s c o n t r i b u t e s i g n i f i c a n t l y t o the  light  1068,  from  NGC  and presumably from other  w e l l . This point w i l l be discussed  total  S e y f e r t s as  f u r t h e r i n Chapter 4.  107  Chapter  4  Conclusions  In s e c t i o n 4 of Chapters limitations  of  emphasized. But raised.  The  the a  2 and  analysis  more  luminosity  3,  the  most  presented  fundamental  here  guestion  distribution  significant  may  "laws"  the c e n t r a l r e g i o n s of g a l a x i e s of  the CCD  o b s e r v a t i o n s - For NGC  contours  of  deVaucouleurs  1566,  comparable  govern  guality  to  f o r example, the i s o p h o t a l  (1973),  based  on  photographic  i n f o r m a t i o n about the i n n e r  cannot  therefore,  determined,  be  observations  p l a t e s , give very l i t t l e be  been  also  which  g a l a x i e s are purely e m p i r i c a l . There are very few of  have  i f these  30".  It  "laws" should  be  expected  to adeguately  detailed  o b s e r v a t i o n s are a v a i l a b l e . A r e l a t e d problem i s t h a t  the  possible  luminosity Clearly,  d e s c r i b e the galaxy s t r u c t u r e when very  influence  of  spiral  arms  or  bars  d i s t r i b u t i o n has not been s u f f i c i e n t l y  dynamical  on  the  considered.  models are needed to provide a b e t t e r b a s i s  on which to d e r i v e a l u m i n o s i t y d i s t r i b u t i o n law. I t should noted  t h a t the o b s e r v a t i o n s presented  Pritchet,  1979)  describe  the  and  i n d i c a t e t h a t the e m p i r i c a l laws do  For such  and  (cf.  adeguately  o b s e r v a t i o n s , a t l e a s t f o r very r e g u l a r s p r i a l s  ellipticals.  are obvious  here and elsewhere  be  For a system such as NGC  1068  however,  s i g n i f i c a n t d e v i a t i o n s from these simple  cases, more i n f o r m a t i o n i s needed.  there laws.  10?  U  *.IO  I  o  '.05'  y  5  4  5  «•  + .10 .o5\ I  -.©SL  "  7  F i g u r e 33: Observed-Convolved r e s i d u a l s f o r the r e d and v i s u a l images o f NGC 1068. The top f i g u r e i s the r e d image, and the bottom f i g u r e i s the v i s u a l image.  109  It  would  photometric  be  very  coverage  Two-dimensional  helpful  of  to  these  observations  in  have  and 0,  B,  V,  colors  components.  NGC  particular,  i n t e r e s t i n g t o see a t 0 and  t o what e x t e n t t h e  B w a v e l e n g t h s , and  longer  wavelengths.  further  investigation  radio has  mapping  any  radio  of  The at  NGC  how  observations  c o u l d be  Observations  of t h e  other  The  unanswered. does n o t  limited  permit  a  the  1068  i t  point source  elongation  various would  is  be  obscured or  also reguires  wavelengths.  More  Seyfert galaxy, i t i s  they  detailed  a f f e c t the  such  as  area disk  distribution. information  advent o f  the  CCD,  low such  1 o f t h i s t h e s i s , "To  a n a l y s i s presented structural  by  the  n o r m a l ? " must  f o r NGC  component  the c o m p l i c a t e d  covered  H/J  feasible.  posed i n C h a p t e r  although  to  emission  p h o t o m e t r y . H<* and  r e g i o n s . With the  detectors,  any  of the  forbidden l i n e s could provide  Seyfert galaxies structurally The  essential  used t o d e t e r m i n e t h e d u s t  a r e much more  reveal  galaxies, the  state  guestion  extent are  I would  would d e t e r m i n e i f t h i s s t r u c t u r e  about the d i f f e r e n t i o n i z a t i o n  observations  and  of  narrow-band o b s e r v a t i o n s  l i n e s , t o d e t e r m i n e how  solid  B,  counterpart.  two-dimensional  noise  Seyferts.  s t r o n g l y peaked i t i s a t I  bar-like  1068  I n a d d i t i o n , f o r any have  for  extensive  other  provide b e t t e r i n f o r m a t i o n about the In  more  1566  and  unigue  s t r u c t u r e o f NGC  CCD  observations  component t o be d e t e r m i n e d ,  and  so a  what  remain NGC  to  1068 these  1068  and  did  not  detailed  110  comparison to be made. But more l i m i t i n g that  not  still  i s the  fact  enough "normal" g a l a x i e s of these Hubble types have  been s t u d i e d with o b s e r v a t i o n s o f t h i s g u a l i t y  with  which  to  compare the S e y f e r t s . Such o b s e r v a t i o n s should be made to make i t p o s s i b l e t o answer t h i s g u e s t i o n .  Ill  Bibliography  Adams, T. F. , 1977, Ap.  J . Supplement, v . 3 3  r  p. 19.  A l l e n , B. J . , B. F. D a r c h y , and B. L a u g u e , 1971, Astronomy and A s t r o p h y s i c s , y.10 , p.198. A l l o i n , D., and J . - P . S a r e y a n , v.33 , p.331. A n d e r s o n , K.  S.,  1970, Ap.  1974, Astronomy and  J . , v. 162  Astrophysics,  , p.743.  A n d r i l l a t , Y., and S. C o l l i n - S o u f f r i n , A s t r o p h y s i c s , y.43 , p . ^ 1 9 .  1975, A s t r o n o m y and  A n d r i l l a t , Y.. , and S. S o u f f r i n , 1971, Astronomy and A s t r o p h y s i c s , v.11 , p.286. A n g e l , J . B . P., H. S. S t o c k m a n , N. J . W o o l f , E. A. B e a v e r , and P. G. H a r t i n , 1976, Ap. J . , v.206 , p. L 5 . E a b a d z h a n y a n t s , M. K., V. A. H a g e n - T o r n , and V. H. L y u t y i , A s t r o f i z i k a , y.8 , p.509. B a r n e s , T. G.,  1968, A s t r o p h y s i c a l L e t t e r s  B a s h , F. N. , 1968, Ap. J . S u p p l e m e n t , v.16  , v.1  , p.171.  , p.373.  B e c k l i n , E. E . , K. Matthews, G. N e u g e b a u e r , and C. W y n n - W i l l i a m s , 1973, Ap. J . , v.186 , p . L 6 9 .  G.  B e r g e , G. L . , and G. A. S e i e l s t a d , 1967, Ap. J . , v.148 Bertola,  F.,  1968, A. J . , v.73  B o k s e n b e r g , A.,  G. W.,  d e B r u y n , A. G., p. 1257.  , p.367.  , p.861.  e t a l , 1978, N a t u r e , V..275 , p.404.  B o l o g n a , J . M., E. F. M c C l a i n , W. K. E o s e , and E..M. 1965, Ap. J . , v.142 , p.106. Erandie,  1972,  and A. H. B r i d l e , and H. L. W.  1974, A. J . , v.79 , p.903..  Sargent,  d e B r u y n , A. G., and A. G. H i l l i s , A s t r o p h y s i c s , v.33 , p.351.  Sloanaker,  1978, A. J . , v.83 ,  1974, Astronomy and  112  deBruyn, A. G., and A. S. Wilson, 1976, Astronomy and A s t r o p h y s i c s , ju53 , p.93. Burbidge, E. M., G. B. Burbidge, and K. H. Prendergast, Ap. J . , v. 130 , p. 26. Cameron,  1959,  M. J . , 1971, M..N. fi. A. S., v. 152 , p.403.  Cannon, B. D., M. V. Penstcn, and E. A. B r e t t , 1971, M. N. fi. A. VJJ.J52  ,  p.  79.  C a r l s o n , W. J . , and C. B. F o l t z ,  1979, Ap. J . , v.233 , p.39.  Cohen, M. H., E. J . Gundermann, and D. E. H a r r i s , 1967, Ap. J . , lt±§0 , P.767. Condal, A. B. , 1979, Ph.D. Columbia.  T h e s i s , O n i v e r s i t y of B r i t i s h  Condal, A. B., G. G. Fahlman, and P. Monger, 1979, i n "Proceedings of the T r i e s t e Conference on Image P r o c e s s i n g i n Astronomy , to be p u b l i s h e d . 11  D i b a i , E.,A., and V. I. P r c n i k , 1965, A s t r o f i z i k a ,  v.1 , p.78.  Dombrovskii, V. A. and V. A. Hagen-Torn, 1968, A s t r o f i z i k a , , p.78.  v.1  Dombrovskii, V. A., M. K. Babadzhanyants, V. A..Hagen-Torn, and S. M. G u t k e v i c h , 1971, A s t r o f i z i k a , .v. 77 , p.471. E i l e k , J . A., Jm B. Auman, T. J . O l r y c h , G. A. H. Walker, and L. V. Kuhi, 1973, Ap. J . , v_.J182 , p. 363. E l i a s , J . M., D. J . E n n i s , D. Y. Gezart, M. G. Hauser, J . B. Houck, . K. Y. Lo, K. Matthews, D. Nadeau, G. Neugebauer, M. W. Werner, and W. E. Westerbrock, 1978, Ap. J . , v.220 , p.25. E l v i s , M., T. Maccaro, A. S. Wilson, M. J . Ward, M. V. Penston, E. A. W. Fosbury, and G. C. P e r o l a , 1978, M. N. B. A. S., v. 183 , p. 129. Elvius,  A., 1978, Astronomy and A s t r o p h y s i c s , y.65 , p.233.  Elvius,  A., and J . S. H a l l , 1965, A. J . v,70 , p.138.  E p s t e i n , G. E., and W. G. Fogarty, 1968,A. J . , v.73 , p.873. Evans, D. S., 1956, V i s t a s In Astronomy , v.2, p.1556.  113  F a h l m a n , G. G., S. H. M o c h n a c k i , C. P r i t c h e t , A. C o n d a l , and G. A. H. W a l k e r , 1978, i n " P r o c e e d i n g s o f t h e S e v e n t h Symposium c n P h o t o e l e c t r i c Image D e v i c e s " , e d . by M c M u l l a n and M o r g a n , E e r f o r t B e p r o d u c t i o n s , p.375. F o g a r t y , W. G., E. E. E p s t e i n , J.W. Montgomery, D w o r e t s k y , 1971, A. J . , v.76 , p.537. F o g a r t y , W. G., E. E. E p s t e i n , and J . Mottman, v.191 , p.305. F o m a l o n t , E. B., and A. T. M o f f e t ,  and M.  1974, Ap. J . ,  1 9 7 1 , A. J . , v.76 , p . 5 .  F r e e m a n , K. C., i n G a l a x i e s and t h e q n i v e r s e e d . by A. M. S a n d a g e , and J . K r i s t i a n , U n i v e r s i t y o f C h i c a g o p.409. £  Gehrels,  T.,  M.  Sandage, Press,  1972, Ap. J . , v.173 , p.123.  G i n z b u r g , V. L . , and L. M. O z e r n o y , 1977, A s t r o p h y s i c s and S p a c e S c i e n c e , v. 50 , p. 23. G l a s p e y , J . W., J . A . E i l e k , G. G. F a h l m a n , and J . B. Auman, 1976, Ap. J . , v.203 , p . 3 3 5 . G l a s s , I . S., Grandi,  1973, M. N. B. A. S., v.164  S. A. , 1978, Ap. J . , v.221  H a r p e r , D. A.,  and F. J . Low,  , p.155.  , p.501.  1 9 7 3 , Ap. J . , v.182  H a r p e r , D. A., F. J . Low, G. H. B i e k e , 1 9 7 2 , Ap. J . , v. 177 , p . L 2 1 . Heckman, T. M., B. B a l i c k , and W. v.224, , p.745.  , p.L89.  and K. B. A r m s t r o n g ,  T. S u l l i v a n ,  1978, Ap. J . ,  H i l d e b r a n d , B. H., S. E. Whitcomb, P. W i n s t o n , B. T. S t i e n i n g , D. A. H a r p e r , and S. H. M o s e l e y , 1977, Ap. J . , v.216 , p. 6 98. B o d g e , P. W. , .1968, A. J . , v. 73 , p.846. Howard, W. p. 1 .  E., and S. P. M a r a n , 1964, Ap. J . S u p p l e m e n t , v.10  J a m e s o n , E. F., A. J . L o n g m o r e , J . A. M c L i n n , and K . J . W o o l f , 1 9 7 4 a , Ap. J . , v. 187 , p . L 1 0 9 . J a m e s o n , B. F., A. J . L o n g m o r e , J . A. M c L i n n , and N . J . W o o l f ,  ,  114  1974b, Ap. J . , v.190 , p.353. Jones, T. W., C. M. Leung, fi. J . Gould, and W. A. S t e i n , 1977, Johnson, h. 1., 1966, ann. r e v . astronomy and A s t r o p h y s i c s , v.4, p. 193. ap. j . , v.212 , p. 52. J u r a , M., B. W. Hobhs, and S. P. Maran, 1978, A. J . , v.83 , p.153. Kellermann, K. I . , and D. I . K. P a u l i n y - T o t h , A s t r o p h y s i c a l l e t t e r s , y. 8 , p.153.  1971,  Kellermann, K. I . , B. G. C l a r k e , D. I . Jauncey, M. H. Cohen, D. B. S h a f f e r , A. T. Moffet, and S. G u l k i s , 1970, Ap. J . , v*jL6J * p-803. K e l l o g g , E., H. Gursky, C. Leung, E. S c h r e i e r , H. Tananbaum, and E. G i a c c c n i , 1971, Ap. J . , v.165 , p.L49. Kemp, J . C., B. . D. H o l s t e n c r o f t , and J . B. Swedlund, 1972, Ap. - » v»j73 , p.I113. J  K h a c h i k i a n , E . Y., and D. W. Weedman, 1971, A s t r o f i z i k a , p.389.  VJS.7  ,  K h a c h i k i a n , E. Y., and D. W. Weedman, 1974, Ap. J . , v.192 , p.581. King, I . E., 1966, A. J . , y«71 , p-64. King, I. B., 1978, Ap. J . , v . 2 2 2  , p.1.  Kleinmann, D. E. , and F, J . Low, 1970, Ap. J . , v. 159 , p.L165. Kleinmann, D« E., and E. L. Wright, 1974, Ap. J . , v. 191 , p.L19. Kleinmann, D. E., F. G. G i l l e t t , and E. L. Wright, 1976, Ap. J . , y. 208 , p. 4 2. . ' Knacke, B. F., and R. W. Capps, 1974, Ap. J . , v.192 , p . L l 9 . Kormendy, J . , 1977, Ap. J . , v.217 , p.406. Koski,  A. T., 1978, Ap. J . , v.223 , p.56.  Kruzewski, A., 1971, Acta Astronomica, y.21 , p.311. K u r i l ' c h i k , V. N., A. E . . A n d r i e v s k i i , V. N. Ivanov, and E. E. Spangenberg, 1970, Soviet Astronomy-A. J . , v.13 , p.881.  115  L a n d s t r e e t , J . D., and J . R. P. A n g e l , 1 9 7 2 , Ap. J . , y.17 4 , P.L127. L e b o f s k y , M. J . , 6. H. B i e k e , a n d J . C..Kemp, 1978, Ap. J . , 1*112 t P- 9 5. L e w i s , B. M., 1 9 7 2 , I . A. 0. Symposium No.44, E x t e r n a l G a l a x i e s and Q u a s a r s ^ e d . by D. S. E v a n s , D o r d r e c h t , B e i d e l , P.267. Low, F. J . , a n d H. H. Aumann, 1 9 7 0 , Ap. J . , y.162 , p . L 7 9 . Low, F. J . , and D. E. K l e i n m a n n , 1 9 6 8 , A. J . , v. 7 2 , p.868. Low, F. J . , a n d G. H. B i e k e ,  1 9 7 1 , N a t u r e , v.233  .p.256.  Lyutyi,  V. M. , 1 9 7 3 , S o v i e t A s t r o n o m y - A . J . , v.16 , p.763.  Lyutyi,  V. Ii. , 1 9 7 7 , S o v i e t A s t r o n o m y - A . J . , v.21 , p.655.  M a l t b y , P., a n d G. A,. S e i e l s t a d , 1 9 6 6 , Ap. J . , y. 144 , p. 216. M a r t i n , W. I., 1 9 7 4 , M. N. If. A. S., V . J 6 8  , p.109.  M c C u t c h e o n , W. H., and P. C. G r e g o r y , 1 9 7 8 , A. J . , y.8 3 -, p . 5 6 6 . M o r o z , V. I . , a n d E. A. D i b a i , v.12 , p.184. Nandy, K., and E. W o l s t e n c r o f t ,  1968, S o v i e t Astronomy-A. J . , 1 9 7 0 , N a t u r e , y.228 , p . 6 2 1 .  N e u g e b a u e r , G., G. G a r m i r e , G. H. B i e k e , and F. J . Low, 1 9 7 2 , Ap. J . , y.166 , p . L 4 5 . N e u g e b a u e r , G., E. E. B e c k l i n , J . B. Oke, and I . S e a r l e , 1 9 7 6 , Ap. . 0. , .v. 205 , . 29. p  Nikulin, J.,  N,. S., V. M. K u v s h i n o v , a n d A. B. S e v e r n y , 1 9 7 1 , Ap. . y. J 7 0 , p . L 5 3 .  N o r d s i e c k , K. H. , 1 9 7 2 , A s t r o p h y s i c a l L e t t e r s , y.12 , p . 6 9 . 0 ' D e l l , S. L., J• J . P u s c h e l l , W. A. S t e i n , a n d J . W. 1978, Ap. J.,Supplement, y.38 , p.267.  Warner,  Osmer, P. S.,. M. G. S m i t h , and D. W. Weedman, 1974, Ap. J . , v.189 , p.187. O s t e r b r o c k , D. E., and B. A. P a r k e r , p.892.  1 9 6 5 , Ap. J . , v 141 , f  116  Pacholcyzyk,  A. G.,  1970, Ap.  J . , v.161  Pacholcyzyk, p.394.  A. G.,  and w.  Wisniewski,  z.  P a s t o r i z a , fl., and fi. G e r o l a , p. 155.  , p.L207. 1967, Ap. J . , v.147  1970, A s t r o p h y s i c a l  Letters,  v. 6 ,  P e n s t o n , M. V., M . J . P e n s t o n , P. A. S e l m e s , E. E. B e c k l i n , G. N e u g e b a u e r , 1974, ft. N. fi. A. S., v.169 , p.357. Pettit,  E . , 1954, Ap. J . , v.120  P r i t c h e t , C.,  1979, Ap.  R e e s , M. J . , V. 1. 1969, N a t u r e , R i c h s t o n e , D. 0., Rieke,  Silk, v.223  , p.354.  and J . L. S e r s i c ,  1975,  M. N. R.  and D . C .  M o r t o n , 1975, Ap.  J . v . 226  J . , v.201  , p.289.  H.,  1978, Ap.  B i e k e , G.  H.,  and F. J . Low,  1972,  Ap.  J . / v. 176  , p.L95.  R i e k e , G.  H.,  and F. J . l o w , 1975,  Ap.  J . , v.199  , p.Ll3..  and D. G. S t e i g e r w a l d , 1977, Ap.  J . , v.217  Sandage, A., 1961, Hubble A t l a s Carnegie I n s t i t u t e . Sandage,  A.,  Schorn, J.  ,  ,  Ap. J . , v.178  P.L177. , p.617.  B. A., E. E. E p s t e i n , J . P. O l i v e r , S. L. S o t e r , and W i l s o n , 1968, Ap,. J . , Vil5J , p.L27.  Schweizer, Sersic,  , p. 550.  Of G a l a x i e s , W a s h i n g t o n ,  1967, Ap. J . , v.150  S c h i l d , fi. F. , 1972,  A.  M, W. Werner, and N. C. W i c k r a m a s i n g h e , , p.788.  G.  B o b e r t s , M. S., p.883.  and  , p.413.  J . , v. 231  Q u i n t a n a , H., P. Kaufmann, S . , y. 17 3 , p. 57 p.  F. , 1979, Ap,. J . , _y. 233  J . L.,  ,  , p. 23.  1957, O b s e r v a t o r y , y . 7 7  Seyfert,  C. K.,  1943, Ap^  J . , v-97  Shields,  G. A.,  and J . B. Oke,  , p.146.  , p.28.  1975, Ap. J . , v.197  , p.5.  W.  117  Shobbrook. fi. fi., 1966a, M.N. fi. A. S., v. 131 , p. 293. Shobbrook. R. R. , 1966b, M. N. B. A. S. , v. 131 , p. 351. Simon, T., and H. M. Dyck, 1975, M. N. B. A. S., v.17 2 , p.19p.. Smith, M. G. , D. W. Weedman, and H. S p i n r a d , 1972, A s t r o p h y s i c a l Letters, i a J J  # p.21.  S o u f f r i n , S., 1969, Astronomy and A s t r o p h y s i c s , y.1 , p.305. S t e i n , W. A., and D.W.  Weedman, 1976, Ap. J . , v.205 , p.44.  S t e i n . W. A., F. C. G i l l e t t , v. 187 , p.213.  a n d K . M. M e r r i l l , 1974, Ap. J . ,  Strom, B. G., 1973, Astronomy and A s t r o p h y s i c s , y. 25 , p.303. Stall,  M. A., 1971, A. J . , y.76 , p.1.  T e l e s c o , C. M., D. A. Harper, and fi. F. Lowenstein, 1976, Ap. XaiOJ , p . L 5 3 . Thompson, B. I . , M. J . Lebofsky, and G. H. Bieke, 1978, Ap. J . , Viii2  >' P-L4 9.  Ulmer, M. P., and S. S. Murray, 1976, Ap. J . , v.207 , p.364. deVaucouleurs, G., 1953, M. N. fi. A. S., v.113 , p.134. deVaucouleurs, G. , 1973, Ap. J . , v. 181 , p.31. . deVaucouleurs, G., and A. deVaucouleurs, 1961, Mem. B. A. S., v.68 , p. 69. deVaucouleurs, G., and A. deVaucouleurs, 1961, P u b l . Dept. of Astronomy, Univ. of Texas, S e r i e s 2, v.2 , No.7. deVaucouleurs, G., and A. deVaucouleurs, 1974, C o n t r i b u t i o n s O b s e r v a t o r i o A s t r o f i s i c a Asiago, No.300-bis, p.101. deVaucouleurs, G., and M. C a p a c c i o l i , v.40 , p.699.  1979, Ap. J . Supplement,  Visvanathan, N., and J . B. Oke, 1968, Ap. J . , y.152 , p.L165. Walker, M. F., 1964, A. J . , v-69 , p.682. Walker, M. F., 1968, Ap. J . , v.151 , p. 71.  118 _  Wampler,  E . J . , 1968,  Wampler-,  E. J . , 1971, Ap- J . , y-164  Wardle,  A p - J . , v . ,154 ,  J . F . C . , and E - A . S r a m e k ,  Weedman, D. p.69.  W. ,  Westerlund,  B . E . , and J , . V .  Wright,  A. E. ,  Yankulova,  I.  1977,  1974, M.,  p.1.  1974,  Ap. J . , v.189  ,  p.399.  A n n . B e v . Astronomy and A s t r o p h y s . , y . i 5  H.  1975,  Z a s o v , A . V . , and V . v.17 , p.169.  ,  p.L53.  Wall,  1969, A . J . , v . 7 4  ,  p.335.  Astronomy-A. J . , v.18 ,  p.720.  N. E . A . S . , v . 1 6 7 Soviet  M. l y u t y i ,  1973,  ,  Soviet  p.273.  Astronomy-A. J . ,  ,  119  Appendix  The  luminosity  multi-aperture deVaucouleurs  profile  photometry  f o l l o w i n g the procedure  and d e V a u c o u l e u r s  c o n s i s t s of p l o t t i n g  these p o i n t s .  distance  can  be  derived  by  several  better to  the  ,  drawbacks  accuracy  make a n o t i c e a b l e In  of  the  due  photometry  t o t h i s p r o c e d u r e . To b e g i n  with,  photometric  measurements  An e r r o r o f t h i s s i z e  difference  c a s e c f NGC  in  variability  deVaucouleurs sorting  of  (1974)  the  account  the  (Figure  particular  so  that  only  derived  19), as  nucleus.  i s  no  i s sufficient luminosity  1068, t h e V p h o t o m e t r y much  shows an as  0.4  3, t h i s i s p r o b a b l y DeVaucouleurs  and  f o r v a r i a b i l i t y i n NGC 4151 by  the photometric data according  observations,  of  1068.. 1068  As d i s c u s s e d i n s e c t i o n 2 o f C h a p t e r to  o f NGC  NGC  even g r e a t e r s c a t t e r t h a n t h i s mag.  curve  n u l /  do t h i s f o r t h e B p h o t o m e t r y  t h a n .1 m a g n i t u d e .  profile.  smooth  numerical differencing of t h i s  H o w e v e r , an e x a m i n a t i o n o f t h e  typically  a  V a l u e s o f s u r f a c e b r i g h t n e s s as a f u n c t i o n o f  deVaucouleurs  reveals  from t h e photometry  g r a p h , and f i t t i n g  curve, through the eguation  The  d e s c r i b e d by  (1974). B r i e f l y , t h e procedure  the p o i n t s determined  on a m a g n i t u d e - v s - a p e r t u r e to  o f a g a l a x y c a n be d e r i v e d f r o m  to  the  observations  time  taken  of  the  during  l e v e l o f a c t i v i t y of t h e n u c l e u s a r e combined.  a  For  120  NGC  1068,  this  separately  means t h a t each s e t o f p h o t o m e t r i c  analyzed,  since  no  two  observers  data  have  must  be  coincident  measurements. In  most c a s e s ,  obviously  only  introduces  magnitude-aperture profile which out  derived 4  of  the  to  i s as  much as to  aperture  of F i g u r e  attempt  was  Figure  33,  component  the  convergence problem  contours  of  profiles as  by  as  0.4  the  CCD  profile.  within  with  the  procedure was  are  based  on  from mag  extends  the  various  at large  data  to these  CCD  visual  radii. the  was  This p r o f i l e  fitted  the  dispersion  cited.  An  data,  described after  are  take  no  profiles, image  mean p r o f i l e  CCD  1068  since  for  data  observations  determined  into a disk i n Chapter 20  which i s e n c o u n t e r e d  models of c o u r s e  photometry  CCD  the  achieved  NGC  luminosity  mag.  match t h e  to  the  plotted.  derived  much  0.2  photometric they  are  This  in  the  published  30"  decompose t h e  together  shows  photometry of the  33  made t o  using  A final the  inner  derive a luminosity  profiles  that  the  uncertainty  32  of  s i z e s were u s e d .  were a v a i l a b l e . The  covered  attempting  no  set  is  region  simulated  data,  only  photometry  In  used  each  d i s p e r s i o n i n the  dispersion  the  Figure  or more o b s e r v a t i o n s  The  Within  5 aperture  substantial  curve.  from  t o r=65" but  sets  4 or  and  2.  For  bulge this  iterations. in this  procedure i s  highly  asymmetric.  account  of c o n t o u r  observations  from  through  The shape  circular  121  apertures. the  Thus much o f t h e i n f o r m a t i o n a b o u t t h e s t r u c t u r e o f  galaxy  is  lost  in  c o r r e s p o n d e n c e between t h i s profile  and  that  of  this  method o f  using  the  e g u i v a l e n t r a d i u s a t each i n t e n s i t y so  irregular  not  provide  a s h a p e a s NGC  a sufficiently  procedure.  There  deriving  contour  u s e f u l comaprison with the p r o f i l e  no  luminosity  p l o t s t o d e r i v e an  l e v e l . For a  1068, t h e p h o t o m e t r i c  unbiased  a  i s  galaxy models  with will  p r o f i l e t o make p o s s i b l e a d e r i v e d from t h e c o n t o u r s .  /aa  n  H •X  it  11  M  k  ~  ""  5  »  '  «$"""  F i g u r e 34: L u m i n o s i t y p r o f i l e s f o r the V o b s e r v a t i o n s o f NGC Legend: =Walker (1968) * =Penston e t a l • =Westerlund and * =deVaucouleurs • =CCD d a t a  JO  a.s  J»  d e r i v e d from t h e p u b l i s h e d photometry 1068, t o g e t h e r w i t h t h e CCB data  H  (1974) W a l l (1968) (1968)  

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0085593/manifest

Comment

Related Items