  We investigate the effects of AGN feedback on the cosmological evolution of
an isolated elliptical galaxy by performing two-dimensional high-resolution
hydrodynamical numerical simulations. The inner boundary of the simulation is
chosen so that the Bondi radius is resolved. Compared to previous works, the
two accretion modes, namely hot and cold, which correspond to different
accretion rates and have different radiation and wind outputs, are carefully
discriminated and the feedback effects by radiation and wind in each mode are
taken into account. The most updated AGN physics, including the descriptions of
radiation and wind from the hot accretion flows and wind from cold accretion
disks, are adopted. Physical processes like star formation, Type Ia and Type II
supernovae are taken into account. We study the AGN light curve, typical AGN
lifetime, growth of the black hole mass, AGN duty-cycle, star formation, and
the X-ray surface brightness of the galaxy. We compare our simulation results
with observations and find general consistency. Comparisons with previous
simulation works find significant differences, indicating the importance of AGN
physics. The respective roles of radiation and wind feedbacks are examined and
it is found that they are different for different problems of interest such as
AGN luminosity and star formation. We find that it is hard to neglect any of
them, so we suggest to use the names of "cold feedback mode" and "hot feedback
mode" to replace the currently used ones.
