Hard X-ray emission from elliptical galaxies and its contribution to the X-ray background

Abstract

We explore the implications of the discovery of hard, power-law X-ray sources in the spectra of nearby elliptical galaxies for the origin of the X-ray background. The spectra of these sources are consistent with models of thermal bremsstrahlung emission from low radiative efficiency accretion flows around central supermassive black holes and are unique in that they approximately match that of the hard XRB. If such sources, with luminosities consistent with those observed in nearby ellipticals, are present in most early-type galaxies, then their integrated emission may contribute significantly to the XRB. These sources may also contribute to the hard source counts detected in deep X-ray surveys.

emulateapj.sty, to appear in ApJ Letters

References in corpus (3)

• The obscured growth of massive black holes
• The contribution of faint AGN to the hard X-ray background
• The Nearby Optical Galaxy Sample: The Local Galaxy Luminosity Function

Cited by in corpus (6)

• Resolving the extragalactic hard X-ray background
• Testing current synthesis models of the X-ray background
• Quasars and galaxy formation
• Tracing the Nuclear Accretion History of the Red Galaxy Population
• Hot dust in two hard Chandra X-ray sources
• Synchrotron Emission from Hot Accretion Flows and the Cosmic Microwave Background Anisotropy