Models for the X-ray spectra and variability of luminous accreting black holes

DOI10.1002/ASNA.200610677zbMATH Open1117.85324arXivastro-ph/0609703OpenAlexW2081766262WikidataQ68663706 ScholiaQ68663706MaRDI QIDQ3418109

Andrea Merloni, J. Malzac, T. Suebsuwong

Publication date: 2 February 2007

Published in: Astronomische Nachrichten: A Journal on all Fields of Astronomy (Search for Journal in Brave)

Abstract: The X-ray spectra of luminous Seyfert 1 galaxies often appear to be reflection dominated. In a number of Narrow Line Seyfert 1 (NLS1) galaxies and galactic black holes in the very high state, the variability of the continuum and of the iron line are decoupled, the reflected component being often much less variable than the continuum. These properties have been interpreted as effects of gravitational light bending. In this framework, we present detailed Monte-Carlo simulations of the reflection continuum in the Kerr metric. These calculations confirm that the spectra and variability behaviour of these sources can be reproduced by the light bending model. As an alternative to the light bending model, we show that similar observational properties are expected from radiation pressure dominated discs subject to violent clumping instabilities and, as a result, have a highly inhomogeneous two-phase structure. In this model, most of the observed spectral and variability features originate from the complex geometrical structure of the inner regions of near-Eddington accretion flows and are therefore a signature of accretion physics rather than general relativity.

Full work available at URL: https://arxiv.org/abs/astro-ph/0609703

Mathematics Subject Classification ID

Black holes (83C57) Radiative transfer in astronomy and astrophysics (85A25)