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We study the effect of AGN mechanical and radiation feedback on the formation of bulge dominated galaxies via mergers of disc galaxies. The merging galaxies have mass-ratios of 1:1 to 6:1 and include pre-existing hot gaseous halos to properly account for the global impact of AGN feedback. Using smoothed particle hydrodynamics simulation code (GADGET-3) we compare three models with different AGN feedback models: (1) no black hole and no AGN feedback; (2) thermal AGN feedback; and (3) mechanical and radiative AGN feedback. The last model is motivated by observations of broad line quasars which show winds with initial velocities of $v_w ge$ 10,000 km/s and also heating associated with the central AGN X-ray radiation. The primary changes in gas properties due to mechanical AGN feedback are lower thermal X-ray luminosity from the final galaxy - in better agreement with observations - and galactic outflows with higher velocity $sim 1000$ km/s similar to recent direct observations of nearby merger remnants. The kinetic energy of the outflowing gas is a factor of $sim$ 20 higher than in the thermal feedback case. All merger remnants with momentum-based AGN feedback with $v_w sim 10,000$ km/s and $epsilon_w=2 times 10^{-3}$, independent of their progenitor mass-ratios, reproduce the observed relations between stellar velocity dispersion and black hole mass ($M_{rm bh} - sigma$) as well as X-ray luminosity ($L_X - sigma$) with $10^{37.5}$ erg/s $lesssim L_X (0.3-8~{rm keV}) lesssim 10^{39.2}$ erg/s for velocity dispersions in the range of 120 km/s $lesssim sigma lesssim$ 190 km/s. In addition, the mechanical feedback produces a much greater AGN variability. We also show that gas is more rapidly and impulsively stripped from the galactic centres driving a moderate increase in galaxy size and decrease in central density with the mechanical AGN feedback model.
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 th
We examine unresolved nuclear X-ray sources in 57 brightest cluster galaxies to study the relationship between nuclear X-ray emission and accretion onto supermassive black holes (SMBHs). The majority of the clusters in our sample have prominent X-ray
The importance of the radiative feedback from SMBHs at the centers of elliptical galaxies is not in doubt, given the well established relations among electromagnetic output, black hole mass and galaxy optical luminosity. In addition, feedback due to
Using hydrodynamic simulations of disc-galaxy major mergers, we investigate the star formation history and remnant properties when various parametrizations of a simple stellar feedback model are implemented. The simulations include radiative cooling,
An extraordinary recent development in astrophysics was the discovery of the fossil relationship between central black hole mass and the stellar mass of galactic bulges. The physical process underpinning this relationship has become known as feedback