The XMM-LSS survey

We present a first catalogue of X-ray sources resulting from the central area of the XMM-LSS (Large Scale Structure survey). We describe the reduction procedures and the database tools we developed and used to derive a well defined catalogue of X-ray sources. The present catalogue is limited to a sub-sample of 286 sources detected at in the 1 deg2 area covered by the photometric VVDS (VIRMOS VLT Deep Survey), which allows us to provide optical and radio identifications. We also discuss the X-ray properties of a larger X-ray sample of 536 sources detected at > in the full 3 deg2 area of the XMM Medium Deep Survey (XMDS) independently of the optical identification. We also derive the relationship for a sample of more than one thousand sources that we discuss in the context of other surveys at similar fluxes.