The impact of cooling flows on the T X − L Bol relation for the most X - ray luminous clusters

The impact of cooling flows on the T X − L Bol relation for the most X-ray luminous clusters. ABSTRACT We examine the effects of cooling flows on the T X − L Bol relation for a sample of the most X-ray luminous (L Bol > 10 45 erg s −1) clusters of galaxies known. Using high-quality ASCA X-ray spectra and ROSAT images we explicitly account for the effects of cooling flows on the X-ray properties of the clusters and show that this reduces the previously-noted dispersion in the T X − L Bol relationship. More importantly, the slope of the relationship is flattened from L Bol ∝ T 3 X to approximately L Bol ∝ T 2 X , in agreement with theoretical predictions. We find no evidence for evolution in the T X − L Bol relation within z ∼ 0.4. Our results demonstrate that the effects of cooling flows must be accounted for before cosmological parameters can be determined from X-ray observations of clusters. The results presented here should provide a reliable basis for modelling the T X − L bol relation at high X-ray luminosities.