The Analogous Structure of Accretion Flows in Supermassive and Stellar Mass Black Holes
Abstract
Over the past 20 years, several lines of evidence have suggested a connection between the structure of black hole accretion flows in active galactic nuclei (AGN) and Galactic X-ray binaries, despite their factor of ~10^8 difference in black hole mass. In particular, both the fundamental plane of black hole accretion and X-ray variability properties now suggest some link between the low-luminosity/hard-spectrum accretion state of X-ray binaries and low-luminosity AGN. However, it is still unclear whether the exact structure and geometry of the disk-corona system in X-ray binaries directly scale up in mass to AGN, and whether this analogy still holds when the accretion flow switches between different accretion states. I will present a novel approach to testing the X-ray binary/AGN connection, based on direct comparisons of faded ‘changing-look quasars’ to X-ray binary outbursts. Using Chandra X-ray and ground-based rest-UV observations of faded changing-look quasars, we probe the evolving geometry of their accretion flows as a function of Eddington ratio, based on the observed spectral changes. We find that the observed spectral evolution in fading quasars displays a remarkable similarity to accretion state transitions in X-ray binary outbursts. Our results show that the structures of black hole accretion flows directly scales across a factor of 10^8 in black hole mass and across different accretion states, thus enabling us to securely apply theoretical models of X-ray binaries to explain AGN phenomenology.
- Publication:
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AAS/High Energy Astrophysics Division
- Pub Date:
- March 2019
- Bibcode:
- 2019HEAD...1710644R