Outflows, Bubbles, and the Role of the Radio Jet: Direct Evidence for AGN Feedback at z~2

TL;DR

This study provides direct evidence of powerful AGN-driven outflows in high-redshift radio galaxies, supporting the role of AGN feedback in quenching star formation and shaping galaxy evolution.

Contribution

It presents the first direct observations of kpc-scale ionized gas outflows driven by AGN at z~2-3, highlighting their potential to terminate star formation in massive galaxies.

Findings

Outflows contain up to a few x 10^10 solar masses of ionized gas.

Outflow velocities are near the escape velocity of massive galaxies.

Kinetic energies are about 0.2% of the black hole's rest mass.

Abstract

To accommodate the seemingly "anti-hierarchical" properties of galaxies near the upper end of the mass function within our hierarchical paradigm, current models of galaxy evolution postulate a phase of vigorous AGN feedback at high redshift, which effectively terminates star formation by quenching the supply of cold gas. Using the SINFONI IFU on the VLT, we identified kpc-sized outflows of ionized gas in z~2-3 radio galaxies, which have the expected signatures of being powerful AGN-driven winds with the potential of terminating star formation in the massive host galaxies. The bipolar outflows contain up to few x 10^10 M_sun in ionized gas with velocities near the escape velocity of a massive galaxy. Kinetic energies are equivalent to ~0.2% of the rest mass of the supermassive black hole. We discuss the results of this on-going study and the global impact of the observed outflows.