Radiative feedback from quasars and the growth of massive black holes in stellar spheroids |
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Authors: | S Yu Sazonov J P Ostriker L Ciotti R A Sunyaev |
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Institution: | Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85740 Garching bei München, Germany;Space Research Institute, Russian Academy of Sciences, Profsoyuznaya 84/32, 117997 Moscow, Russia;Institute of Astronomy, Madingley Road, Cambridge CB3 0HA;Department of Astronomy, University of Bologna, via Ranzani 1, I-40127 Bologna, Italy |
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Abstract: | We discuss the importance of feedback via photoionization and Compton heating on the co-evolution of massive black holes (MBHs) at the centre of spheroidal galaxies, and their stellar and gaseous components. We first assess the energetics of the radiative feedback from a typical quasar on the ambient interstellar medium (ISM). We then demonstrate that the observed M BH–σ relation could be established following the conversion of most of the gas of an elliptical progenitor into stars, specifically when the gas-to-stars mass ratio in the central regions has dropped to a low level ~0.01 or less, so that gas cooling is no longer able to keep up with the radiative heating by the growing central massive black hole (MBH). A considerable amount of the remaining gas will be expelled and both MBH accretion and star formation will proceed at significantly reduced rates thereafter, in agreement with observations of present-day ellipticals. We find further support for this scenario by evolving over an equivalent Hubble time a simple, physically based toy model that additionally takes into account the mass and energy return for the spheroid evolving stellar population, a physical ingredient often neglected in similar approaches. |
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Keywords: | galaxies: active galaxies: evolution quasars: general |
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