AGN radiative feedback in dusty quasar populations
  New populations of hyper-luminous, dust-obscured quasars have been recently
discovered around the peak epoch of galaxy formation ($z \sim 2-3$), in
addition to similar sources found at lower redshifts. Such dusty quasars are
often interpreted as sources `in transition', from dust-enshrouded starbursts
to unobscured luminous quasars, along the evolutionary sequence. Here we
consider the role of the active galactic nucleus (AGN) radiative feedback,
driven by radiation pressure on dust, in high-luminosity, dust-obscured
sources. We analyse how the radiation pressure-driven dusty shell models, with
different shell mass configurations, may be applied to the different
populations of dusty quasars reported in recent observations. We find that
expanding shells, sweeping up matter from the surrounding environment, may
account for prolonged obscuration in dusty quasars, e.g. for a central
luminosity of $L \sim 10^{47}$erg/s, a typical obscured phase (with extinction
in the range $A_{V} \sim 1-10$ mags) may last a few $\sim 10^6$yr. On the other
hand, fixed-mass shells, coupled with high dust-to-gas ratios, may explain the
extreme outflows recently discovered in red quasars at high redshifts. We
discuss how the interaction between AGN radiative feedback and the ambient
medium at different temporal stages in the evolutionary sequence may contribute
to shape the observational appearance of dusty quasar populations.
