clusters of galaxies
I.K. Rozgacheva, I.B. Kuvshinova
Last ten years the interest to studying physical properties of intracluster gas in clusters of galaxies has grown. It is connected to accumulation of the observation data on the intracluster medium, and appeared in this connection an opportunity of the solution of fundamental problems of physics of galaxies. The observation facts which have been dis-covered due to development of extra-atmospheric methods of observations last third XX centuries, and conclusions from them are discussed. Note, that the mechanism of heating of interacluster gas, formation of cooling flow, and very low contents of cold gas remain unresolved questions of physics of rich clusters of galaxies. Their solution is actual for understanding of dynamics of clusters, and demands complex studying of properties of radiation of intracluster plasma. With this purpose the statistical analysis of properties of 170 rich clusters of galaxies from the catalogue of rich clusters of galaxies with cooling flows (I.K. Rozgacheva and I.B. Kuvshinova, 2005; I.B. Kuvshinova, 2009) is performed. The fact of existence of the correlations discovered earlier by other authors between x-ray luminosity and temperature of intracluster gas, velocity dispersion of galaxies and x-ray luminosity of intracluster gas in clusters is confirmed. New anticorrelation be-tween optical luminosity and x-ray luminosity of intracluster gas in clusters is discovered: . Clusters of galaxies form sequences with various values of parameter . Values of parameter for these sequences are close. Note, that clusters of galaxies have various properties. The discovered sequences are evidence that the mass of intracluster gas in various clusters can strongly differ.