1997/09/26 by John P. Hughes, Hughes, John P.
Earth and Planetary Sciences · Physics and Astronomy · #Astro and Planetary Science #Astrophysical Phenomena and Observations #Astrophysics (astro-ph) #FOS: Physical sciences #High-pressure geophysics and materials #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9709272
4 pages, including 2 postscript figs, LaTeX. To appear in the proceedings of the conference "A New Vision of an Old Cluster: Untangling Coma Berenices" (held June 17-20, 1997, Marseille, France)
arxiv created 1997/09/26 · openalex publication_date 1997/09/26 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
I re-examine mass estimates of the Coma cluster from pre-ASCA X-ray spectral observations. A large range of model dark matter distributions are examined, under the assumptions of hydrostatic equilibrium and spherical symmetry, to determine the widest possible allowed range on the total mass of the cluster. Within a radius of 1 Mpc, the total cluster mass is tightly constrained to be (6.2 +/- 0.9) x 10**14 solar masses and the ratio of luminous baryonic matter to total matter lies between 13% and 17%. Within a radius of 3 Mpc the total mass is (1.3 +/- 0.5) x 10**15 solar masses and the luminous matter fraction is 20%-40%. I find that the ``universal'' dark matter density profile proposed by Navarro, Frenk, and White, based on N-body simulations of a standard cold-dark-matter dominated Universe, predicts a steep temperature gradient within the core of the cluster that is a poor fit to the Coma data and can be rejected at greater than 99% confidence.