AGN feedback in elliptical galaxies with AXIS (Helen Russell)

Feedback from AGN is thought to be the essential mechanism slowing massive galaxy growth at late times in the Universe. Chandra observations of the hot atmospheres surrounding these galaxies reveal cavities, weak shocks, sound waves and filaments, demonstrating the substantial energy input by repeated episodes of AGN activity. Our current understanding is predominantly driven by deep Chandra observations of the nearest, richest cluster atmospheres. Although remarkable, these behemoths are clearly unrepresentative of the wider galaxy population driving the slowdown in star formation at low redshift. AXIS's sensitivity at low energies coupled to high spatial resolution will reveal radio-mode feedback in typical Milky-Way-sized galaxies and determine whether cooling and star formation are regulated as effectively in lower-mass systems as in clusters.