Feedback from central black holes in elliptical galaxies. III: models
  with both radiative and mechanical feedback
  We find, from high-resolution hydro simulations, that winds from AGN
effectively heat the inner parts (~100 pc) of elliptical galaxies, reducing
infall to the central SMBH; and radiative (photoionization and X-ray) heating
reduces cooling flows at the kpc scale. Including both types of feedback with
(peak) efficiencies of 3 10^{-4} < epsilon_mech < 10^{-3} and of epsilon_rad
~10^{-1.3} respectively, produces systems having duty-cycles, central SMBH
masses, X-ray luminosities, optical light profiles, and E+A spectra in accord
with the broad suite of modern observations of massive elliptical systems. Our
main conclusion is that mechanical feedback (including all three of energy,
momentum and mass) is necessary but the efficiency, based on several
independent arguments must be a factor of 10 lower than is commonly assumed.
Bursts are frequent at z>1 and decline in frequency towards the present epoch
as energy and metal rich gas are expelled from the galaxies into the
surrounding medium. For a representative galaxy of final stellar mass ~3
10^{11} Msun, roughly 3 10^{10} Msun of recycled gas has been added to the ISM
since z~2 and, of that, roughly 63% has been expelled from the galaxy, 19% has
been converted into new metal rich stars in the central few hundred parsecs,
and 2% has been added to the central SMBH, with the remaining 16% in the form
hot X-ray emitting ISM. The bursts occupy a total time of ~170 Myr, which is
roughly 1.4% of the available time. Of this time, the central SMBH would be
seen as an UV or optical source for ~45% and ~71$% of the time, respectively.
Restricting to the last 8.5 Gyr, the burst occupy ~44 Myr, corresponding to a
fiducial duty-cycle of ~5 10^{-3}.
