Accretion in Strong Gravity: From Galactic to Supermassive Black Holes

Abstract

The galactic black hole binary systems give an observational template showing how the accretion flow changes as a function of increasing mass accretion rate, or L/L_Edd. These data can be synthetised with theoretical models of the accretion flow to give a coherent picture of accretion in strong gravity, in which the major hard-soft spectral transition is triggered by a change in the nature and geometry of the inner accretion flow from a hot, optically thin plasma to a cool, optically thick accretion disc. However, a straightforward application of these models to AGN gives clear discrepancies in overall spectral shape. Either the underlying accretion model is wrong, despite its success in describing the Galactic systems and/or there is additional physics which breaks the simple scaling from stellar to supermassive black holes.

arXiv commentTo appear in the proceedings of "From X-ray Binaries to Quasars: Black Hole Accretion on All Mass Scales" (Amsterdam, July 2004). Eds T.Maccarone, R.Fender, L.Ho. Corrected version: missing figure added

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Cited by in corpus (4)

• Global Structure of Three Distinct Accretion Flows and Outflows around Black Holes through Two-Dimensional Radiation-Magnetohydrodynamic Simulations
• A Combined Optical and X-ray Study of Unobscured Type 1 AGN. I. Optical Spectra and SED Modeling
• Anisotropy of X-ray bursts from neutron stars with concave accretion disks
• Broad iron emission lines in Seyfert Galaxies - re-condensation of gas onto an inner disk below the ADAF