The Effect of the AGN Feedback on the Interstellar Medium of Early-Type
  Galaxies: 2D Hydrodynamical Simulations of the Low-Rotation Case
  We present 2D hydrodynamical simulations for the evolution of early-type
galaxies containing central massive black holes (MBHs), starting at age 2 Gyr.
The code contains accurate and physically consistent radiative and mechanical
AGN wind feedback, with parsec-scale central resolution. Mass input comes from
stellar evolution; energy input includes Type Ia and II supernova and stellar
heating; star-formation is included. Realistic, axisymmetric dynamical models
for the galaxies are built solving the Jeans' equations. The lowest mass models
(Mstar = 8 10^{10}Msun) develop global outflows sustained by SNIa's heating,
ending with a significantly lower amount of hot gas and new stars. In more
massive models, nuclear outbursts last to the present epoch, with large and
frequent fluctuations in nuclear emission and from the gas (Lx). Each burst
last ~ 10^{7.5} yr, during which (for r < 2-3 kpc) cold, inflowing, and hot,
outflowing gas phases coexist. The Lx-T relation for the gas matches that of
local galaxies. AGN activity causes positive feedback for star formation.
Roughly half of the total mass loss is recycled into new stars (DeltaMstar),
just ~ 3% of it is accreted on the MBH, the remainder being ejected from the
galaxy. The ratio between the mass of gas expelled to that in to new stars, the
load factor, is ~0.6. Rounder galaxies shapes lead to larger final MBH masses,
DeltaMstar, and Lx. Almost all the time is spent at very low nuclear
luminosities, yet one quarter of the total energy is emitted at an Eddington
ratio > 0.1. The duty-cycle of AGN activity approximates 4% (Abridged).
