Observational signatures of galactic winds powered by active galactic nuclei

Abstract

We predict the observational signatures of galaxy scale outflows powered by active galactic nuclei (AGN). Most of the emission is produced by the forward shock driven into the ambient interstellar medium (ISM) rather than by the reverse shock. AGN-powered galactic winds with energetics suggested by phenomenological feedback arguments should produce spatially extended ~1-10 keV X-ray emission ~1041-44 erg s-1, significantly in excess of the spatially extended X-ray emission associated with normal star-forming galaxies. The presence of such emission is a direct test of whether AGN outflows significantly interact with the ISM of their host galaxy. We further show that even radio-quiet quasars should have a radio luminosity comparable to or in excess of the far-infrared-radio correlation of normal star-forming galaxies. This radio emission directly constrains the total kinetic energy flux in AGN-powered galactic winds. Radio emission from AGN wind shocks can also explain the recently highlighted correlations between radio luminosity and the kinematics of AGN narrow-line regions in radio-quiet quasars.