Speaker
Description
In idealized, dynamically relaxed galaxies, groups or clusters, the central galaxy is expected to reside at the bottom of the gravitational potential well, coinciding with the peaks of the multiphase cooling gas - hot, warm, and cold - that flows in to fuel star formation and the central supermassive black hole (SMBH). However, spatial offsets between the central galaxy and these gas phases are known to occur and may significantly affect SMBH fueling. A key implication of a multiphase AGN feeding scenario is that if any gas phase directly fuels the AGN, then a sustained offset between this gas phase and the core of the galaxy should correspond to a quiescent SMBH. In this talk, I will present results from our recent study of 25 central galaxies spanning low-mass groups and high-mass clusters (13.2 < logM_500 < 14.8). Using a combination of Chandra, MUSE, and VLBA observations, we examined spatial offsets of hot and warm gas in the atmospheres of these galaxies and explored their influence on SMBH activity. Based on the presence or absence of a compact radio core (from VLBA) and the distribution of multiphase gas, we found strong indications that it is the warm gas peaking at the galaxy’s center – rather than the hot X-ray gas – that plays a decisive role in triggering SMBH activity. I will conclude by showing early results on the cold molecular phase from archival and new ALMA observations of CO around these galaxies. Our work represents a step forward in linking the active/quiescent state of the central SMBH of the most massive galaxies to all the gas phases involved in the baryon cycle.