The Luminosity Function of X-ray Point Sources in Centaurus A
Abstract
We have studied the X-ray point source population of Centaurus A (NGC 5128) using data from four archival CHANDRA observations. We detected 272 point-like X-ray sources within a radius of 10 arcmin from the centre. Approximately half of these are CXB sources, with the remaining half being LMXBs. The spatial distribution of the LMXBs, both azimuthally averaged and 2-D, is consistent with the distribution of the K-band light observed in the 2MASS survey. After correction for the incompleteness effect we constrain the LMXB luminosity function down to 2 times 10^{36} erg/s, much lower than previous studies of LMXBs in elliptical galaxies. The obtained XLF flattens significantly below L_X = 5 times 10^{37} erg/s and follows the dN/dL proportional to 1/L law in agreement with the behaviour found earlier for LMXBs in the Milky Way and in the bulge of M31.
Cite
@article{arxiv.astro-ph/0505250,
title = {The Luminosity Function of X-ray Point Sources in Centaurus A},
author = {R. Voss and M. Gilfanov},
journal= {arXiv preprint arXiv:astro-ph/0505250},
year = {2009}
}
Comments
18 pages, 9 figures, Accepted by A&A Various small changes and new appendix