2009/11/02 by Daniel S. Hudson, Rupal Mittal, Thomas H. Reiprich +3 · 1 citation
Physics and Astronomy · #astro-ph.CO
paper · pdf · doi:10.1051/0004-6361/200912377
45 pages, 19 figures, 7 tables. Accepted for publication in A&A. Contact Person: Rupal Mittal ([email protected])
arxiv created 2009/11/02 · arxiv updated 2015/05/14
We use the largest complete sample of 64 galaxy clusters (HIghest X-ray FLUx Galaxy Cluster Sample) with available high-quality X-ray data from Chandra, and apply 16 cool-core diagnostics to them, some of them new. We also correlate optical properties of brightest cluster galaxies (BCGs) with X-ray properties. To segregate cool core and non-cool-core clusters, we find that central cooling time, tcool, is the best parameter for low redshift clusters with high quality data, and that cuspiness is the best parameter for high redshift clusters. 72% of clusters in our sample have a cool core (tcool < 7.7 h71-1/2 Gyr) and 44% have strong cool cores (tcool <1.0 h71-1/2 Gyr). For the first time we show quantitatively that the discrepancy in classical and spectroscopic mass deposition rates can not be explained with a recent formation of the cool cores, demonstrating the need for a heating mechanism to explain the cooling flow problem. [Abridged]