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The self-regulated AGN feedback loop: the role of chaotic cold accretion

Published online by Cambridge University Press:  17 August 2016

M. Gaspari*
Affiliation:
Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA email: mgaspari@astro.princeton.edu; Einstein & Spitzer Fellow
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Abstract

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Supermassive black hole accretion and feedback play central role in the evolution of galaxies, groups, and clusters. I review how AGN feedback is tightly coupled with the formation of multiphase gas and the newly probed chaotic cold accretion (CCA). In a turbulent and heated atmosphere, cold clouds and kpc-scale filaments condense out of the plasma via thermal instability and rain toward the black hole. In the nucleus, the recurrent chaotic collisions between the cold clouds, filaments, and central torus promote angular momentum cancellation or mixing, boosting the accretion rate up to 100 times the Bondi rate. The rapid variability triggers powerful AGN outflows, which quench the cooling flow and star formation without destroying the cool core. The AGN heating stifles the formation of multiphase gas and accretion, the feedback subsides and the hot halo is allowed to cool again, restarting a new cycle. Ultimately, CCA creates a symbiotic link between the black hole and the whole host via a tight self-regulated feedback which preserves the gaseous halo in global thermal equilibrium throughout cosmic time.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2016 

References

Anderson, M. E., Gaspari, M., White, S. D. M., Wang, W., & Dai, X. 2014, MNRAS, 449, 3806 CrossRefGoogle Scholar
Bondi, H. 1952, MNRAS, 112, 195 Google Scholar
Gaspari, M., Melioli, C. & Brighenti, D'Ercole, A. 2011a, MNRAS, 411, 349 CrossRefGoogle Scholar
Gaspari, M., Brighenti, F., D'Ercole, A., & Melioli, C. 2011b, MNRAS, 415, 1549 CrossRefGoogle Scholar
Gaspari, M., Ruszkowski, M., & Sharma, P. 2012a, ApJ, 746, 94 Google Scholar
Gaspari, M., Brighenti, F., & Temi, P. 2012b, MNRAS, 424, 190 CrossRefGoogle Scholar
Gaspari, M., Ruszkowski, M., & Oh, S. P. 2013a, MNRAS, 432, 3401 CrossRefGoogle Scholar
Gaspari, M., Brighenti, F., & Ruszkowski, M. 2013b, AN, 334, 394 Google Scholar
Gaspari, M. & Churazov, E. 2013c, A&A, 559, A78 Google Scholar
Gaspari, M., Brighenti, F., Temi, P., & Ettori, S. 2014a, ApJ, 783, L10 Google Scholar
Gaspari, M., Churazov, E., Nagai, D., Lau, E. T., & Zhuravleva, I. 2014b, A&A, 569, A67 Google Scholar
Gaspari, M. 2015a, MNRAS, 451, L60 Google Scholar
Gaspari, M., Brighenti, F., Temi, P., & Ettori, S. 2015b, A&A, 579, 62 Google Scholar
Hudson, D. S., Mittal, R., Reiprich, T. H., & Nulsen, P. E. J. 2010, A&A, 513, 37 Google Scholar
Humphrey, P. J., Buote, D. A., Brighenti, F., Gebhardt, K., et al. 2009, ApJ, 703, 1257 CrossRefGoogle Scholar
McNamara, B. R., Nulsen, P. E. J. 2012, New J. Phys., 14, 055023 Google Scholar
Russell, H. R., Fabian, A. C., McNamara, B. R., & Broderick, A. E. 2015, MNRAS, 451, 588 Google Scholar
Sanders, J. S. & Fabian, A. C. 2013, MNRAS, 429, 2727 Google Scholar
Voit, G. M., Donahue, M., Bryan, G. L., & McDonald, M. 2015, Nature, 519, 203 CrossRefGoogle Scholar
Werner, N., Oonk, J. B. R., Sun, M., Nulsen, P. E. J., et al. 2014, MNRAS, 439, 2291 Google Scholar
Wong, K.-W., Irwin, J. A., Shcherbakov, R. V., Yukita, M., et al. 2014, ApJ, 780, 9 Google Scholar