X-ray source population study of the starburst galaxy M 83 with XMM-Newton^{⋆,⋆⋆,⋆⋆⋆}

¹ Institut für Astronomie und Astrophysik, Eberhard Karls Universität, Sand 1, 72076 Tübingen, Germany
e-mail: ducci@astro.uni-tuebingen.de
² Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstraße, 85741 Garching, Germany

Received: 3 January 2013
Accepted: 5 March 2013

Abstract

Aims. We present the results obtained from the analysis of three XMM-Newton observations of M 83. The aims of the paper are studying the X-ray source populations in M 83 and calculating the X-ray luminosity functions of X-ray binaries for different regions of the galaxy.

Methods. We detected 189 sources in the XMM-Newton field of view in the energy range of 0.2–12 keV. We constrained their nature by means of spectral analysis, hardness ratios, studies of the X-ray variability, and cross-correlations with catalogues in X-ray, optical, infrared, and radio wavelengths.

Results. We identified and classified 12 background objects, five foreground stars, two X-ray binaries, one supernova remnant candidate, one super-soft source candidate and one ultra-luminous X-ray source. Among these sources, we classified for the first time three active galactic nuclei (AGN) candidates. We derived X-ray luminosity functions of the X-ray sources in M 83 in the 2–10 keV energy range, within and outside the D₂₅ ellipse, correcting the total X-ray luminosity function for incompleteness and subtracting the AGN contribution. The X-ray luminosity function inside the D₂₅ ellipse is consistent with that previously observed by Chandra. The Kolmogorov-Smirnov test shows that the X-ray luminosity function of the outer disc and the AGN luminosity distribution are uncorrelated with a probability of ~99.3%. We also found that the X-ray sources detected outside the D₂₅ ellipse and the uniform spatial distribution of AGNs are spatially uncorrelated with a significance of 99.5%. We interpret these results as an indication that part of the observed X-ray sources are X-ray binaries in the outer disc of M 83.