X-ray source counts at high galactic latitude from measurements of fluctuations in the X-ray background

Open Access
Publisher Website
Google Scholar
Abstract
We use measurements of small-scale fluctuations in the intensity of the X-ray background to extend the X-ray source counts to a flux level an order of magnitude fainter than the limit of present catalogues. The source counts are found to be consistent with the Euclidean form over the full range of measurement. By comparing the observations with predicted source count relations, we determine constraints to the X-ray luminosity function of active galaxies. It is possible without invoking cosmological evolution to find forms of the luminosity function which are compatible with the observed source counts and which account for up to 50 per cent of the intensity of the X-ray background (2–10keV). However, reasonable assumptions concerning the X-ray luminosity and evolution of QSOs enable the whole X-ray background to be explained.

This publication has 0 references indexed in Scilit: