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Dark Matter and Metal Abundances in Elliptical Galaxies from X-ray Observations of the Hot ISM

Michael Loewenstein
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Abstract

I review the results of recent analysis and interpretation of X-ray observations of elliptical galaxies, focusing on elemental abundances and dark matter. The hot ISM is characterized by subsolar Fe abundances and solar Si-to-Fe ratios; and, I compare these with stellar abundances and discuss implications of these measurements. From models constructed to explain X-ray temperatures and their correlation with optical properties in a complete sample of ellipticals, I demonstrate the ubiquity of dark matter in bright elliptical galaxies, present limits on dark matter structural parameters, and discuss the scaling of dark halos with optical luminosity. The visual mass-to-light ratio within six optical effective radii has a universal value of 25 (for a Hubble constant of 80 km/sec/Mpc) that conflicts with the simplest extension of CDM theories of large scale structure formation to galactic scales.

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Michael Loewenstein. 1998-08-19. Dark Matter and Metal Abundances in Elliptical Galaxies from X-ray Observations of the Hot ISM. https://arxiv.org/abs/astro-ph/9808204

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