Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-12-07
MNRAS, 384, 2008, p. 361-369
Astronomy and Astrophysics
Astrophysics
10 pages, 9 figures, accepted by MNRAS
Scientific paper
10.1111/j.1365-2966.2007.12713.x
We study light curves and spectra (equivalent widths of the iron line and some other spectral characteristics) which arise by reflection on the surface of an accretion disc, following its illumination by a primary off-axis source - an X-ray 'flare', assumed to be a point-like source just above the accretion disc resulting in a spot with radius dr/r<1. We consider General Relativity effects (energy shifts, light bending, time delays) near a rotating black hole, and we find them all important, including the light bending and delay amplification due to the spot motion. For some sets of parameters the reflected flux exceeds the flux from the primary component. We show that the orbit-induced variations of the equivalent width with respect to its mean value can be as high as 30% for the observer's inclination of 30 degrees, and much more at higher inclinations. We calculate the ratio of the reflected flux to the primary flux and the hardness ratio which we find to vary significantly with the spot phase mainly for small orbital radii. This offers the chance to estimate the lower limit of the black hole spin if the flare arises close to the black hole.
Dovciak Michael
Goosmann Rene W.
Karas Vladimir
Matt Giorgia
No associations
LandOfFree
Variation in the primary and reprocessed radiation from an orbiting spot around a black hole does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Variation in the primary and reprocessed radiation from an orbiting spot around a black hole, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Variation in the primary and reprocessed radiation from an orbiting spot around a black hole will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-120589