Accretion of Interstellar Matter by Massive Objects.

Salpeter, E. E.

doi:10.1086/147973

Cited by 790 publications

(550 citation statements)

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“…We define the mass ratio Mbh/Mbh,expect at which an AGN phase begins as ∆Mswitch, and allow its value to be a free parameter in the model. When an AGN phase begins, the BH grows according to the Salpeter (or e-folding) time (Salpeter 1964):…”

Section: Dark Matter Halo Galaxy and Black Hole Growthmentioning

confidence: 99%

A unifying evolutionary framework for infrared-selected obscured and unobscured quasar host haloes

DiPompeo

Hickox

Myers

2016

Mon. Not. R. Astron. Soc.

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Recent measurements of the dark matter halo masses of infrared-selected obscured quasars are in tension -some indicate that obscured quasars have higher halo mass compared to their unobscured counterparts, while others find no difference. The former result is inconsistent with the simplest models of quasar unification that rely solely on viewing angle, while the latter may support such models. Here, using empirical relationships between dark matter halo and supermassive black hole masses, we provide a simple evolutionary picture that naturally explains these findings and is motivated by more sophisticated merger-driven quasar fueling models. The model tracks the growth rate of haloes, with the black hole growing in spurts of quasar activity in order to "catch-up" with the M bh -M stellar -M halo relationship. The first part of the quasar phase is obscured and is followed by an unobscured phase. Depending on the luminosity limit of the sample, driven by observational selection effects, a difference in halo masses may or may not be significant. For high luminosity samples, the difference can be large (a few to 10 times higher masses in obscured quasars), while for lower luminosity samples the halo mass difference is very small, much smaller than current observational constraints. Such a simple model provides a qualitative explanation for the higher mass haloes of obscured quasars, as well as rough quantitative agreement with seemingly disparate results.

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Section: Dark Matter Halo Galaxy and Black Hole Growthmentioning

confidence: 99%

A unifying evolutionary framework for infrared-selected obscured and unobscured quasar host haloes

DiPompeo

Hickox

Myers

2016

Mon. Not. R. Astron. Soc.

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“…Debuhr et al (2011Debuhr et al ( , 2012, Di Matteo et al (2005), we furthermore limit the black hole accretion rate to the Eddington limiṫ (Eddington 1921). Here M BH is the black hole mass and τ S = η × 4.5 × 10 8 yr the Salpeter time-scale (Salpeter 1964). Each time step the total amount of massṀ w t and momentum (ṗ rad +ṗ w ) t made available by the AGN are calculated and equally distributed among the SPH-particles within a radius 2R acc .…”

Section: Agn Feedbackmentioning

confidence: 99%

Viscous time lags between starburst and AGN activity

Blank

Duschl

2016

Mon. Not. R. Astron. Soc.

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There is strong observational evidence indicating a time lag of order of some 100 Myr between the onset of starburst and AGN activity in galaxies. Dynamical time lags have been invoked to explain this. We extend this approach by introducing a viscous time lag the gas additionally needs to flow through the AGN's accretion disc before it reaches the central black hole. Our calculations reproduce the observed time lags and are in accordance with the observed correlation between black hole mass and stellar velocity dispersion.Key words: galaxies: active -galaxies: formation -galaxies: interactions -galaxies: nucleiquasars: general -galaxies: starburst. I N T RO D U C T I O NMotivated by, for instance, observed correlations between the mass of an AGN's central black hole and the host galaxy's velocity dispersion (e.g. Gebhardt et al. 2000) and between black hole mass and bulge mass (e.g. Kormendy & Richstone 1995), there is an ongoing debate whether, and if so, how starbursts and AGN are connected to each other.Di , for instance, explain such correlations as due to a thermal AGN feedback that heats the gas of the galaxy and thus prevents further star formation and AGN activity: more massive galaxies have a deeper gravitational potential well, thus the black hole has to gain more mass before its luminosity is capable of expelling the gas from the galaxy and quenching star formation and AGN activity. This then leads to the velocity dispersion and the bulge mass, respectively, to be related to the black hole mass. In these simulations starburst and AGN activity occur simultaneously, but recent observations show that AGN activity may be delayed with regard to star formation activity by time-scales of 50-250 Myr (e.g. Davies et al. 2007;Schawinski et al. 2009;Wild, Heckman & Charlot 2010).Hopkins (2012) argues that such a time lag can occur for purely dynamical reasons. His high spatial resolution simulations of galaxy mergers show first an inward motion of gas towards the dynamical centre giving rise to (a burst of) star formation. In these models, the gas flowing further inwards can do so only by losing angular momentum by gravitational instabilities. This, in turn, gives rise to a time lag between star formation and AGN activity.We extend this idea by modelling the loss of angular momentum and the ensuing inflow in the framework of an accretion disc scenario. Thus the time lag between starburst and AGN activity consists of a dynamical lag given by the time span the gas needs to E-mail: mblank@astrophysik.uni-kiel.de reach the accretion disc and a subsequent viscous lag given by the time span the gas needs to flow through the accretion disc until it reaches the black hole.In Section 2 we explain our numerical methods and the setup of the merger event that is, in this scenario, responsible for the inflow of gas to the newly forming galactic centre. In Section 3 we present and discuss the general picture that results from our calculations. As our model depends on a number of parameters, we perform a parameter stud...

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“…Matter around the hole is attracted by the black hole gravity, it is compressed, heated, and then radiates. This was realized quite soon (Salpeter 1964;Zeldovich 1964;Lynden-Bell 1969;Shakura & Sunjaev 1973) 1 .…”

Section: Introductionmentioning

confidence: 98%