Archive | 2021
Gauging the effect of supermassive black holes feedback on quasar host galaxies
Abstract
In order to gauge the role that active galactic nuclei (AGN) play in the evolution of galaxies via the effect of kinetic feedback in nearby QSO 2’s (z∼ 0.3), we observed eight such objects with bolometric luminosities Lbol ∼ 1046ergs−1 using Gemini GMOSIFU’s. The emission lines were fitted with at least two Gaussian curves, the broadest of which we attributed to gas kinetically disturbed by an outflow. We found that the maximum extent of the outflow ranges from ∼1 to 8 kpc, being ∼0.5±0.3 times the extent of the [O iii] ionized gas region. Our ‘default’ assumptions for the gas density (obtained from the [S ii] doublet) and outflow velocities resulted in peak mass outflow rates of Ṁ out ∼ 3 – 30 M yr−1 and outflow power of Ė out ∼ 1041 – 1043 ergs−1. The corresponding kinetic coupling efficiencies are ε f = Ė def out /Lbol ∼ 7×10−4 – 0.5 %, with the average efficiency being only 0.06 % (0.01 % median), implying little feedback powers from ionized gas outflows in the host galaxies. We investigated the effects of varying assumptions and calculations on Ṁout and Ėout regarding the ionized gas densities, velocities, masses and inclinations of the outflow relative to the plane of the sky, resulting in average uncertainties of one dex. In particular, we found that better indicators of the [O iii] emitting gas density than the default [S ii] line ratio, such as the [Ar iv]λλ4711,40 line ratio, result in almost an order of magnitude decrease in the ε f .