M 33 Chandra X-Ray Point Source Catalog

The observations were centered on the nucleus and on the star-forming region NGC 604. A total of 261 sources were detected in an area of about 0.2 square degrees down to a flux limit of 3 x 10<sup>-16</sup> erg/s/cm<sup>2</sup>, which corresponds to a luminosity of ~2 x 10<sup>34</sup> erg/s at a distance of 840 kpc.

The luminosity functions of the X-ray sources observed in M 33 have been constructed and are consistent with those of other star-forming galaxies, taking into account background contamination. In addition, the combination of X-ray color analysis and the existence of "blue" optical counterparts strongly indicates that the X-ray point source population in M 33 consists of young objects. Above 3 x 10<sup>35</sup> erg/s, there are few X-ray sources in the locus of the X-ray hardness ratio diagram that is generally populated by low-mass X-ray binaries.