Dark Matter and Metal Abundances in Elliptical Galaxies from X-ray Observations of the Hot ISM
Abstract
Description
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.
16 pages Latex including 11 encapsulated postscript files, uses paspcon.sty and psfig.sty, to appear in Star Formation in Early-Type Galaxies, ASP Conf. Ser., eds. P. Carral and J. Cepa
16 pages Latex including 11 encapsulated postscript files, uses paspcon.sty and psfig.sty, to appear in Star Formation in Early-Type Galaxies, ASP Conf. Ser., eds. P. Carral and J. Cepa