Self-regulated star formation and the black hole-galaxy bulge relation

Abstract

We show that star formation in galaxy bulges is self-regulating through momentum feedback, limiting the stellar bulge mass to Mb α σ4. Together with a black hole mass MBH α σ4 set by active galactic nucleus (AGN) momentum feedback, this produces a linear MBH-Mb relation. At low redshift this gives MBH/Mb ~ 10-3, close to the observed ratio. We show that AGN feedback can remove any remaining gas from the bulge and terminate star formation once the central black hole reaches the MBH-σ value, contrary to earlier claims. We find a mild upward deviation from the σ4 law at higher redshift and at higher σ. © 2011 The Authors. Monthly Notices of the Royal Astronomical Society © 2011 RAS.