AN INVESTIGATION OF COOLING FLOWS AND GENERAL CLUSTER PROPERTIES FROMAN X-RAY IMAGE DEPROJECTION ANALYSIS OF 207 CLUSTERS OF GALAXIES

In this paper we present an X-ray image deprojection analysis of Einst ein Observatory imaging data on 207 clusters of galaxies. The resultin g radial profiles for luminosity, temperature and electron density var iations are determined from the cluster surface-brightness profiles ac cording to gravitational potential constraints from average X-ray temp eratures and optical velocity dispersions. This enables us to determin e cooling flow and other cluster properties, such as baryon fractions, Sunyaev-Zel'dovich microwave decrements and Thomson depths. From the results we have compiled a catalogue of the detected cooling flows, an d investigated their effects on general cluster properties. To assist in the analysis, we have constructed self-consistent correlations betw een the cluster X-ray luminosity, temperature and optical velocity dis persion, using 'orthogonal distance' regression to account for errors in both dimensions of the data. These fits indicate that, in general, the temperatures of clusters are isothermal, and that they have spectr al p-values consistent with unity (if the dependence of luminosity on temperature is assumed to be quadratic). We find that the X-ray lumino sity, temperature and optical velocity dispersion relations depend sig nificantly on the cooling flow mass-deposition rate, through character istic differences in the density profiles. Clusters of similar cooling flow mass-deposition rate exhibit self-similar density profiles, with larger cooling flows showing higher central densities. This leads to scatter in the luminosity-related correlations within the X-ray lumino sity, temperature and optical velocity dispersion plane. The segregati on in density also leads to dispersion in other related properties suc h as 'half-light radii' and baryon fractions. The baryon fraction in t he cores of cooling flow clusters appears to be higher, but as the den sity profiles tend to a similar value at larger radii, irrespective of cooling flow property, so too do the baryon fraction profiles appear to rise to a concordant value of greater than 10 per cent at 1 Mpc. Th us this sample indicates that clusters, as a whole, are inconsistent w ith primordial nucleosynthesis baryon fraction prediction, for a flat universe, of 6 per cent.