OPTICAL FILAMENTS AND GLOBAL FLOW IN CLUSTER COOLING FLOWS

Many cooling flow clusters have optical filaments with anomalously high luminosities which require that some energy source sustains the filaments at optically emitting temperatures for much longer than their instantaneous cooling times. In an effort to constrain the energy source for powering these optical filaments, we try to supplement previously discovered correlations of filament properties with other cooling flow and cluster characteristics. We find that all cooling flow clusters with high radio rotation measures at their centers also have optical filaments or nuclear emission. Both high rotation measures and filaments may be independent characteristics of cooling flows, but there may also be a causal relationship: for example, magnetic reconnection in magnetized cooling flows may power the optical luminosities of filaments condensing out of the flows. We also find that filament properties are correlated with the peculiar velocities of their associated central dominant galaxies, a more global cluster characteristic. We consider ways in which this correlation could be causal.