An enormous molecular gas flow in the RXJ0821+0752 galaxy cluster
  We present recent {\it Chandra} X-ray observations of the RXJ0821.0+0752
galaxy cluster in addition to ALMA observations of the CO(1-0) and CO(3-2) line
emission tracing the molecular gas in its central galaxy. All of the CO line
emission, originating from a $10^{10}\,M_{\odot}$ molecular gas reservoir, is
located several kpc away from the nucleus of the central galaxy. The cold gas
is concentrated into two main clumps surrounded by a diffuse envelope. They
form a wide filament coincident with a plume of bright X-ray emission emanating
from the cluster core. This plume encompasses a putative X-ray cavity that is
only large enough to have uplifted a few percent of the molecular gas. Unlike
other brightest cluster galaxies, stimulated cooling, where X-ray cavities lift
low entropy cluster gas until it becomes thermally unstable, cannot have
produced the observed gas reservoir. Instead, the molecular gas has likely
formed as a result of sloshing motions in the intracluster medium induced by a
nearby galaxy. Sloshing can emulate uplift by dislodging gas from the galactic
center. This gas has the shortest cooling time, so will condense if disrupted
for long enough.
