Stellar and AGN feedback in isolated early-type galaxies: the role in
  regulating star formation and ISM properties
  Understanding how galaxies maintain the inefficiency of star formation with
physically self-consistent models is a central problem for galaxy evolution.
Although numerous theoretical models have been proposed in recent decades, the
debate still exists. By means of high-resolution two-dimensional hydrodynamical
simulations, we study the three feedback effects (the stellar wind heating, SNe
feedback, and AGN feedback) in suppressing star formation activities on the
evolution of early-type galaxies with different stellar masses. AGN feedback
models are updated based on \citet{Yuan2018}. The gas sources comes exclusively
from the mass losses of dying low-mass stars for most of our models. We find
that SNe feedback can keep star formation at a significantly low level for low
mass elliptical galaxies for a cosmological evolution time. For the high mass
galaxies, AGN feedback can efficiently offset the radiative cooling and thus
regulate the star formation activities. Such a suppression of star formation is
extremely efficient in the inner region of the galaxies. AGB heating cannot
account for this suppression for low and high mass galaxies. The X-ray
temperature $T_{\rm X}$ and luminosity $L_{\rm X}$ of hot plasma can be in
agreement with the observed data with the inclusion of effective feedback
processes. These results thus suggest that we can use $T_{\rm X}$ and $L_{\rm
X}$ to probe the role of different feedback processes. The inclusion of
additional gas sources can make the mass scale between SNe and AGN feedback
dominating in suppressing star formation decrease to an observationally
inferred value of a few $10^{10}~M_{\odot}$.
