Diffuse Gas and X-ray Binary Populations in Elliptical Galaxies

Raymond E. White III(University of Alabama)

[Invited Review Talk, 30 min.]


The impact of recent Chandra observations on our understanding of the X-ray emission from normal elliptical galaxies will be reviewed. Chandra's high angular resolution can resolve emission from stellar X-ray binaries out of the diffuse X-ray emission from gaseous atmospheres within ellipticals. Resolving out the spectrally hard binary component from the softer gaseous component allows more accurate spectral analysis of each component. Chandra spectroscopy indicates that gaseous elemental abundances are subsolar, i.e. lower than those of the central stars. This is not well understood but is in agreement with prior ASCA and ROSAT results. Improved spectral and luminosity constraints on global populations of X-ray binaries will also be described. Variations in the X-ray binary populations (per unit galaxian optical luminosity) are correlated with variations in the specific frequency of globular clusters in ellipticals. This indicates that X-ray binaries are largely formed in globular clusters, rather than being a primordial field population.



Himel Ghosh