IRAS 13224-3809
Orbiting spot around black hole
Relativistic lines from accretion discs
The Rapid Burster
Relativistic LinesThe most striking feature of the Fe line is that it can be very broad (inferred Doppler velocities up to ~ c/3). In the first studied case of the Seyfert 1 galaxy MCG-6-30-15, the galaxy exhibits a relativistically broadened shape. This was interpreted in terms of Doppler shifts produced by the disk rotation, aberration, and gravitational redshift in the red horn due to the proximity to the black hole's event horizon. [Ref 4]Currently relativistic lines have been measured in some AGNs, but not in all of them, the reason for this being still an open issue. Iwasawa et al., 2004 [Ref 22] reported the detection in NGC 3516 of a spectral feature at 6.1 keV, in addition to a stable 6.4-keV line, with the energy of the peak moving between 5.7 and 6.5 keV. The spectral evolution of the feature agrees with Fe K emission arising from a spot on the accretion disc, illuminated by a corotating flare. This opens the best known method to measure Black Hole masses. |
| IRAS 13224-3809 | Orbiting spot around black hole | Relativistic lines from accretion discs | The Rapid Burster |