A Spatially-Resolved Survey of Distant Quasar Host Galaxies: I. Dynamics of galactic outflows

TL;DR

This study uses integral field spectroscopy to observe ionized gas outflows in eleven high-redshift quasar host galaxies, revealing their velocities, driving mechanisms, and impact on galaxy evolution.

Contribution

It provides the first spatially-resolved analysis of galactic outflows in distant quasar hosts, identifying their driving forces and role in galaxy feedback processes.

Findings

Outflows reach velocities of 500-1700 km/s.

Outflow rates range from 8 to 2400 solar masses per year.

Outflows are the main cause of gas depletion, with no star formation detected along outflow paths.

Abstract

We present observations of ionized gas outflows in eleven z$ =1.39-2.59$ radio-loud quasar host galaxies. Data was taken with the integral field spectrograph (IFS) OSIRIS and the adaptive optics system at the W.M. Keck Observatory targeting nebular emission lines (H$\beta$, [OIII], H$\alpha$, [NII] and [SII]) redshifted into the near-infrared (1-2.4 \micron). Outflows with velocities of 500 - 1700 km\,s$^{-1}$ are detected in 10 systems on scales ranging from $<1$ kpc to 10 kpc with outflow rates from 8-2400 M$_\odot$yr$^{-1}$. For five sources, the outflow momentum rates are 4-80 times $L_{AGN}$/c, consistent with outflows being driven by an energy conserving shock. The five other outflows are either driven by radiation pressure or an isothermal shock. The outflows are the dominant source of gas depletion, and we find no evidence for star formation along the outflow paths. For eight objects, the outflow paths are consistent with the orientation of the jets. Yet, given the calculated pressures, we find no evidence of the jets currently doing work on these galactic-scale ionized outflows. We find that galactic-scale feedback occurs well before galaxies establish a substantial fraction of their stellar mass, as expected from local scaling relationships.