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OSO 8 X-ray spectra of clusters of galaxies. II - DiscussionAn observational description of X-ray clusters of galaxies is given based on OSO 8 X-ray results for spatially integrated spectra of 20 such clusters and various correlations obtained from these results. It is found from a correlation between temperature and velocity dispersion that the X-ray core radius should be less than the galaxy core radius or, alternatively, that the polytropic index is about 1.1 for most of the 20 clusters. Analysis of a correlation between temperature and emission integral yields evidence that more massive clusters accumulate a larger fraction of their mass as intracluster gas. Galaxy densities and optical morphology, as they correlate with X-ray properties, are reexamined for indications as to how mass injection by galaxies affects the density structure of the gas. The physical arguments used to derive iron abundances from observed equivalent widths of iron line features in X-ray spectra are critically evaluated, and the associated uncertainties in abundances derived in this manner are estimated to be quite large.
Document ID
Document Type
Reprint (Version printed in journal)
External Source(s)
Smith, B. W. (NASA Goddard Space Flight Center Laboratory for High Energy Astrophysics, Greenbelt; Maryland, University, College Park, Md., United States)
Mushotzky, R. F. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Serlemitsos, P. J. (NASA Goddard Space Flight Center Laboratory for High Energy Astrophysics, Greenbelt, Md., United States)
Date Acquired
August 9, 2013
Publication Date
January 1, 1979
Publication Information
Publication: Astrophysical Journal
Subject Category
Distribution Limits