The Relation Between Line Emission and Brightest Cluster Galaxies in
  Three Exceptional Clusters: Evidence for Gas Cooling from the ICM
  There is a strong spatial correlation between brightest cluster galaxies
(BCGs) and the peak density and cooling rate of the intra-cluster medium (ICM).
In this paper we combine integral field spectroscopy, CO observations and X-ray
data to study three exceptional clusters (Abell 1991, Abell 3444 and Ophiuchus)
where there is a physical and dynamical offset between the BCG and the cooling
peak to investigate the connection between the cooling of the intracluster
medium, the cold gas being deposited and the central galaxy. We find the
majority of the optical line emission is spatially coincident with the peak in
the soft X-rays. In the case of A1991 we make separate detections of CO(2-1)
emission on the BCG and on the peak of the soft X-ray emission suggesting that
cooling continues to occur in the core despite being offset from the BCG. We
conclude that there is a causal link between the lowest temperature (< 2 keV)
ICM gas and the molecular gas(~ 30K). This link is only apparent in systems
where a transitory event has decoupled the BCG from the soft X-ray peak. We
discuss the prospects for identifying more examples of this rare configuration.
