Feeding and Small-scale Feedback in Low-Luminosity AGNs
Physics and Astronomy
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 n ~ r -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.
Proceedings of the International Astronomical Union
Roman V. Shcherbakov, Frederick K. Baganoff, Ka-Wah Wong and Jimmy Irwin (2012). Feeding and Small-scale Feedback in Low-Luminosity AGNs. Proceedings of the International Astronomical Union, 8, pp 74-77. doi:10.1017/S1743921312019242.
Publisher's Copyright and Source
Copyright © International Astronomical Union 2013.
Originally published in Proceedings of the International Astronomical Union, Volume 8, Symposium S290 (Feeding Compact Objects: Accretion on All Scales), August 2012, pp. 74-77. DOI:http://dx.doi.org/10.1017/S1743921312019242
This is a pre-print version submitted to arXiv.org on 18 Dec 2012. Retrieved from: http://arxiv.org/abs/1212.4494.
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