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Feeding and Small-scale Feedback in Low-Luminosity AGNs

Published online by Cambridge University Press:  21 February 2013

Roman V. Shcherbakov
Affiliation:
Department of Astronomy, University of Maryland, College Park, MD 20742-2421, USA email: roman@astro.umd.edu Hubble Fellow
Frederick K. Baganoff
Affiliation:
Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA, 02139
Ka-Wah Wong
Affiliation:
Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487, USA
Jimmy Irwin
Affiliation:
Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487, USA
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Abstract

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The unmatched X-ray resolution of Chandra allows probing the gas flow near quiescent supermassive black holes (BHs). The radius of BH gravitational influence on gas, called the Bondi radius, is resolved in Sgr A* and NGC 3115. Shallow accretion flow density profiles nr−β with β=0.7–1.0 were found for Sgr A* and NGC 3115 with the help of Chandra. We construct self-consistent models with gas feeding and dynamics from near the Bondi radius to the event horizon to explain the observations. Gas is mainly supplied to the region by hot colliding stellar winds. Small-scale feedback such as conduction effectively flattens the density profile from steep β=1.5 in a Bondi flow. We further constrain density and temperature profiles using the observed radio/sub-mm radiation emitted near the event horizon. We discuss the present state of our numerical model and its qualitative features, such as the role of the galactic gravitational potential and the random motion of wind-emitting stars.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2013

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