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We have created a new, clean catalogue of extragalactic non-nuclear X-raysources by correlating the 3XMM-DR4 data release of the XMM-NewtonSerendipitous Source Catalogue with the Third Reference Catalogue of BrightGalaxies and the Catalogue of Neighbouring Galaxies, using an improved versionof the method presented in Walton et al. (2011). Our catalogue contains 1,314sources, of which 384 are candidate ultraluminous X-ray sources (ULXs). Theresulting catalogue improves upon previous catalogues in its handling ofspurious detections by taking into account XMM-Newton quality flags. Weestimate the contamination of ULXs by background sources to be 24 per cent. Wedefine a 'complete' subsample as those ULXs in galaxies for which thesensitivity limit is below $10^{39}$ erg/s and use it to examine the hardnessratio properties between ULX and non-ULX sources, and ULXs in different classesof host galaxy. We find that ULXs have a similar hardness ratio distribution tolower-luminosity sources, consistent with previous studies. We also find thatULXs in spiral and elliptical host galaxies have similar distributions to eachother independent of host galaxy morphology, however our results do supportprevious indications that the population of ULXs is more luminous instar-forming host galaxies than in non-star-forming galaxies. Our cataloguecontains further interesting subpopulations for future study, includingEddington Threshold sources and highly variable ULXs. We also examine thehighest-luminosity (L$_X$ > $5 \times 10^{40}$ erg/s) ULXs in our catalogue insearch of intermediate-mass black hole candidates, and find nine new possiblecandidates.

A new, clean catalogue of extragalactic non-nuclear X-ray sources in nearby galaxies