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Abstracts
4/6
Phil Hopkins
Harvard University
Black Hole Feedback: Uniting Mergers, Quasars, and Red Galaxy
Formation
Observations are increasingly probing each aspect of the evolutionary
model for starbursts, quasars, and spheroidal galaxies, in which
mergers between gas-rich galaxies drive nuclear inflows of gas,
producing intense starbursts and feeding buried growth of
supermassive black holes until feedback expels gas and renders a
briefly visible optical quasar. These observations imply with
increasing emphasis that black hole feedback must play a critical
role. Using a large suite of hydrodynamical simulations of galaxy
mergers we quantify the relation between the different stages of this
evolutionary sequence. Quasar light curves and accretion rate
evolution are qualitatively different when feedback couples to the
surrounding ISM, and the quasar lifetime and column density
distribution can be understood as a function of both instantaneous
and peak quasar luminosity in this regime. We determine these
dependencies and use them to de-convolve the observed quasar
luminosity function to determine the formation and evolution of
quasars and to map this distribution to others in the evolutionary
sequence. With this formalism, we can predict a wide variety of black
hole properties, the X-ray background spectrum, red galaxy
distributions, and ongoing merger starburst fractions and
distributions at redshifts z=0-6, and the structure and signatures of
feedback-driven outflows. Essentially, the bright quasar population
can directly inform our theoretical and observational picture of the
buildup of much more difficult to observe merger, red galaxy, and
ULIRG populations. Black hole feedback is a vital link in these
distributions, and with (but not without) it, these distributions are
all self-consistent and their statistics follow from their being
manifestations of the same fundamental evolutionary process.
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