A Link Between Ram Pressure Stripping and Active Galactic Nuclei
  The dense environment of a galaxy cluster can radically transform the content
of in-falling galaxies. Recent observations have found a significant population
of active galactic nuclei (AGN) within "jellyfish galaxies," galaxies with
trailing tails of gas and stars that indicate significant ram pressure
stripping. The relationship between AGN and ram pressure stripping is not well
understood. In this letter, we investigate the connection between AGN activity
and ram pressure in a fully cosmological setting for the first time using the
RomulusC simulation, one of the highest resolution simulations of a galaxy
cluster to date. We find unambiguous morphological evidence for ram pressure
stripping. For lower mass galaxies (with stellar masses < 10^9.5 solar masses)
both star formation and black hole accretion are suppressed by ram pressure
before they reach pericenter, whereas for more massive galaxies accretion onto
the black hole is enhanced during pericentric passage. Our analysis also
indicates that as long as the galaxy retains gas, AGN with higher Eddington
ratios are more likely to be the found in galaxies experiencing higher ram
pressure. We conclude that prior to quenching star formation, ram pressure
triggers enhanced accretion onto the black hole, which then produces heating
and outflows due to AGN feedback. AGN feedback may in turn serve to aid in the
quenching of star formation in tandem with ram pressure.
