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Line profiles of accretion disks around black holes in Schwarzschild-de Sitter and Einstein-Yang-Mills spacetimes Slobodov, Sergei
Abstract
We investigate the characteristic peaks in the iron line profile in the black hole accretion disk X-ray spectrum in two static spherically symmetric metrics, Schwarzschild-de Sitter metric and the Einstein-Yang-Mills black hole metric. For the Schwarzschild-de Sitter metric our results show that for a fixed mass black hole, the peaks become less pronounced and closer together with increasing cosmological constant A. This effect is mainly due to the slower rotational velocity of Keplerian orbits at large radii in the Schwarzschild-de Sitter spacetime as compared to that for the Schwarzschild spacetime. This change of the iron line profile is similar to that obtained from extending the accretion disk size or reducing the emission power law exponent in the Schwarzschild black hole accretion disk models. Based upon the current estimates of A, black holes of at least 1018 solar masses are required to make the effect observable. For Einstein-Yang-Mills black holes, the line profiles depend strongly on the horizon radius and the solution number n. For n = 1 the profile is similar to that of a Schwarzschild black hole. In contrast, the shallow slope of the g00 component of the metric for n = 2,3,4 solutions increases the line width for these solutions significantly, in some cases creating a second pair of peaks redshifted approximately by a factor of 2, breaking the usual correspondence between the position of the blue peak and the black hole mass. The line profiles of solutions for n = 5 — 8 and higher, depending on the horizon radius, closely resemble that of extreme Reissner-Nordstrom black hole. In addition, due to an island of orbit stability near the Einstein-Yang-Mills black-hole horizon for the solutions with small horizon radius r/, there is an extra pair of peaks in the line profile redshifted by a factor of 30 times or more relative to the main line. These features might be used to distinguish accreting Einstein-Yang-Mills black holes from Schwarzschild and Kerr black holes.
Item Metadata
Title |
Line profiles of accretion disks around black holes in Schwarzschild-de Sitter and Einstein-Yang-Mills spacetimes
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
2003
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Description |
We investigate the characteristic peaks in the iron line profile in the black hole accretion
disk X-ray spectrum in two static spherically symmetric metrics, Schwarzschild-de Sitter
metric and the Einstein-Yang-Mills black hole metric. For the Schwarzschild-de Sitter metric our results show that for a fixed mass black hole,
the peaks become less pronounced and closer together with increasing cosmological constant
A. This effect is mainly due to the slower rotational velocity of Keplerian orbits at large
radii in the Schwarzschild-de Sitter spacetime as compared to that for the Schwarzschild
spacetime. This change of the iron line profile is similar to that obtained from extending
the accretion disk size or reducing the emission power law exponent in the Schwarzschild
black hole accretion disk models. Based upon the current estimates of A, black holes of at
least 1018 solar masses are required to make the effect observable.
For Einstein-Yang-Mills black holes, the line profiles depend strongly on the horizon
radius and the solution number n. For n = 1 the profile is similar to that of a Schwarzschild
black hole. In contrast, the shallow slope of the g00 component of the metric for n = 2,3,4 solutions increases the line width for these solutions significantly, in some cases
creating a second pair of peaks redshifted approximately by a factor of 2, breaking the
usual correspondence between the position of the blue peak and the black hole mass. The
line profiles of solutions for n = 5 — 8 and higher, depending on the horizon radius, closely
resemble that of extreme Reissner-Nordstrom black hole. In addition, due to an island of
orbit stability near the Einstein-Yang-Mills black-hole horizon for the solutions with small
horizon radius r/, there is an extra pair of peaks in the line profile redshifted by a factor
of 30 times or more relative to the main line. These features might be used to distinguish
accreting Einstein-Yang-Mills black holes from Schwarzschild and Kerr black holes.
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Extent |
3427898 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2009-11-03
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0091350
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
2003-11
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.