The luminosity function of X-ray point sources in Centaurus A

Abstract

We studied the population of X-ray point sources in the elliptical galaxy Centaurus A, using archival Chandra data. Within a radius of 10 arcmin from the centre we detected 272 sources. Of these approximately half are LMXBs with the rest being CXB sources. The spatial distribution of the LMXBs is found to be consistent with the distribution of K-band light. We constrain the luminosity function (LF) of the X-ray sources down to ∼2 × 1036 erg s-1. The X-ray LF of the LMXBs flattens significantly below L X ∼ 5 × 1037 erg s-1 and follows the dN/dL ∝ L-1 law in agreement with results from the bulges of spiral galaxies. © 2006 International Astronomical Union.