The XMM-LSS catalogue: X-ray sources and associated optical data. Version I

TL;DR

This paper presents the first 5.5 square degrees of the XMM-LSS X-ray source catalog, including detailed source parameters, optical associations, and data accessibility, facilitating multi-wavelength astrophysical studies.

Contribution

It provides the initial X-ray source catalog with comprehensive parameters, optical associations, and data access, enhancing the utility for multi-wavelength research.

Findings

3385 sources detected above likelihood threshold

Excellent agreement with deep logN-logS distributions

Availability of full X-ray images in FITS format

Abstract

Following the presentation of the XMM-LSS X-ray source detection package by Pacaud et al., we provide the source lists for the first 5.5 surveyed square degrees. The catalogues pertain to the [0.5-2] and [2-10] keV bands and contain in total 3385 point-like or extended sources above a detection likelihood of 15 in either band. The agreement with deep logN-logS is excellent. The main parameters considered are position, countrate, source extent with associated likelihood values. A set of additional quantities such as astrometric corrections and fluxes are further calculated while errors on the position and countrate are deduced from simulations. We describe the construction of the band-merged catalogue allowing rapid sub-sample selection and easy cross-correlation with external multi-wavelength catalogues. A small optical CFHTLS multi-band subset of objects is associated wich each source along with an X-ray/optical overlay. We make the full X-ray images available in FITS format. The data are available at CDS and, in a more extended form, at the Milan XMM-LSS database.