Observations of feedback from radio-quiet quasars – II. Kinematics of ionized gas nebulae

Abstract

The prevalence and energetics of quasar feedback is a major unresolved\nproblem in galaxy formation theory. In this paper, we present Gemini Integral\nField Unit observations of ionized gas around eleven luminous, obscured,\nradio-quiet quasars at z~0.5 out to ~15 kpc from the quasar; specifically, we\nmeasure the kinematics and morphology of [O III]5007 emission. The round\nmorphologies of the nebulae and the large line-of-sight velocity widths (with\nvelocities containing 80% of the emission as high as 1000 km/s combined with\nrelatively small velocity difference across them (from 90 to 520 km/s) point\ntoward wide-angle quasi-spherical outflows. We use the observed velocity widths\nto estimate a median outflow velocity of 760 km/s, similar to or above the\nescape velocities from the host galaxies. The line-of-sight velocity dispersion\ndeclines slightly toward outer parts of the nebulae (by 3% per kpc on average).\nThe majority of nebulae show blueshifted excesses in their line profiles across\nmost of their extents, signifying gas outflows. For the median outflow\nvelocity, we find a kinetic energy flow between 4x10^{44} and 3x10^{45} erg/s\nand mass outflow rate between 2000 and 20000 Msun/yr. These values are large\nenough for the observed quasar winds to have a significant impact on their host\ngalaxies. The median rate of converting bolometric luminosity to kinetic energy\nof ionized gas clouds is ~2%. We report four new candidates for "super-bubbles"\n-- outflows that may have broken out of the denser regions of the host galaxy.\n