Using a simple description of feedback from black hole growth , we develop an analytic model for the fueling of Seyferts ( low-luminosity AGN ) and their relation to their host galaxies , Eddington ratio distributions , and cosmological evolution .
We derive a solution for the time evolution of accretion rates in a feedback-driven blast wave , applicable to large-scale outflows from bright quasars in galaxy mergers , low-luminosity AGN , and black holes or neutron stars in supernova remnants .
Under the assumption that cold gas stochastically accretes onto a central supermassive black hole at a rate set by the dynamics of that gas , our solution determines the evolution of Seyfert light curves .
Using this model , we predict the Seyfert luminosity function , duty cycles and AGN “ lifetimes , ” and the distribution of host morphologies , Eddington ratios , and obscuration as a function of AGN luminosity and black hole mass , and find agreement with observations at z = 0 .
We consider the breakdown of the contribution from this mechanism and from stellar wind and virialized hot gas accretion and merger-driven activity .
We also make specific predictions for the weak evolution of the Seyfert luminosity function ; i.e .
luminosity function of quiescent , as opposed to merger-driven activity , as a function of redshift , and for changes in both the slope and scatter of the M _ { BH } - \sigma relation at low- M _ { BH } .
Our modeling provides a quantitative and physical distinction between local , low-luminosity quiescent AGN activity and violent , merger-driven bright quasars .
In our picture , the quiescent mode of fueling dominates over a wide range of luminosities ( -14 \gtrsim M _ { B } \gtrsim - 22 ) at z = 0 , where most black hole growth occurs in objects with M _ { BH } \lesssim 10 ^ { 7 } M _ { \sun } , in S0 and Sa/b galaxies .
However , quasar activity from gas-rich mergers evolves more rapidly with redshift , and by z = 1 , quiescent fueling is important only at luminosities an order of magnitude or more below the “ break ” in the luminosity function .
Consequently , although non-merger driven fueling is important for black hole growth and the M _ { BH } - \sigma relation at low M _ { BH } , it does not significantly contribute to the black hole mass density of the Universe or to cosmological backgrounds .