Abstract
Abstract We present detailed observations of photoionization conditions and galaxy kinematics in 11 z = 1.39–2.59 radio-loud quasar host galaxies. Data were taken with the OSIRIS integral field spectrograph and the adaptive optics system at the W. M. Keck Observatory that targeted nebular emission lines (Hβ, [O iii], Hα, [N ii]) redshifted into the near-infrared (1–2.4 μm). We detect extended ionized emission on scales ranging from 1 to 30 kpc photoionized by stars, shocks, and active galactic nuclei (AGN). Spatially resolved emission-line ratios indicate that our systems reside off the star formation and AGN-mixing sequence on the Baldwin, Phillips, & Terlevich diagram at low redshift. The dominant cause of the difference between line ratios of low-redshift galaxies and our sample is due to lower gas-phase metallicities, which are 2–5× less compared to galaxies with AGN in the nearby universe. Using gas velocity dispersion as a proxy to stellar velocity dispersion and dynamical mass measurement through inclined disk modeling, we find that the quasar host galaxies are undermassive relative to their central supermassive black hole mass, with all systems residing off the local scaling (M •–σ, M •–M *) relationship. These quasar host galaxies require substantial growth, up to an order of magnitude in stellar mass, to grow into present-day massive elliptical galaxies. Combining these results with part I of our sample paper, we find evidence for winds capable of causing feedback before the AGN host galaxies land on the local scaling relation between black hole and galaxy stellar mass, and before the enrichment of the interstellar medium to a level observed in local galaxies with AGN.
Highlights
Today, feedback from supermassive black holes (SMBHs) is an integral part of galaxy evolution models
The latest observational and theoretical results point to a critical question: at what point does the active galactic nucleus (AGN) drive an outflow powerful enough to clear the galaxy of its gas into the surrounding circumgalactic medium (CGM) (King & Pounds 2015)? According to theoretical work, this typically happens once the galaxy reaches the M–σ relationship (Zubovas & King 2014)
In the quasar host galaxy of 3C 298, we find that the majority of the gas in the outflow is in a molecular state, and once combined with the ionized kinetic luminosity, we find values closer to those predicted in simulations
Summary
Feedback from supermassive black holes (SMBHs) is an integral part of galaxy evolution models. Today’s near-infrared IFSs are not sensitive enough to detect the stellar continuum from the quasar/AGN host galaxies, they can still detect extended ionized emission, enabling us to extract the dynamical properties of the galaxy (Inskip et al 2011; Vayner et al 2017) and compare systems to the local scaling relation. This paper is part II of two papers focusing on understanding the photoionization mechanisms of gas in radio-loud quasar host galaxies and weighing the mass of the galaxy and SMBH to compare them to the local scaling relations. All magnitudes are on the AB scale unless otherwise stated
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