COOLING FLOWS AND THE X-RAY LUMINOSITY TEMPERATURE RELATION FOR CLUSTERS

The luminosity-temperature relation for clusters has a wide dispersion which has been explained as being due to a range of gas density or ma ss. We show here that the offset of a cluster from the mean relation i s proportional to the stren th of its cooling flow. We also confirm a similar effect on the metallicity-temperature relation. Since the cool ing flow itself cannot produce such large effects, we propose that the y are due to a more widespread difference between the intracluster med ia of cooling flow and non-cooling flow clusters. We suggest that the effects may be due to the inhomogeneity of the intracluster medium tha t is required in cooling flows to explain the distributed mass deposit ion. The effects have implications for the cluster temperature functio n and for the evolution of clusters.