THE ROSAT WIDE-FIELD CAMERA ALL-SKY SURVEY OF EXTREME-ULTRAVIOLET SOURCES .2. THE 2RE SOURCE CATALOG

During 1990-1991 the Wide Field Camera (WFC) on the ROSAT satellite pe rformed the first all-sky survey at EUV wavelengths. The survey was co nducted in two 'colours' using broad-band filters to define wavebands covering the ranges 60-140 Angstrom and 112-200 Angstrom. It was fully imaging, with effective spatial resolution of about 3 arcmin FWHM, an d point source location accuracy of typically better than 1 arcmin. Fr om an initial analysis, Pounds et al. published the WFC Bright Source Catalogue (BSC) of 383 sources. In this paper we report results from r eprocessing of the complete survey database; the resulting list of sou rces is the '2RE' Catalogue. It contains 479 sources, of which 387 are detected in both survey wavebands, a significant advance on the BSC ( 80 per cent versus 60 per cent). Improvements over the original BSC in clude: (i) better rejection of poor aspect periods, and smaller random errors in the aspect reconstruction; (ii) improved background screeni ng; (iii) improved methods for source detection; (iv) inclusion of a t ime-variability test for each source; (v) more extensive investigation of the survey sensitivity. We define the catalogue selection criteria , and present the catalogue contents in terms of tables and sky maps. We also discuss the sky coverage, source number-flux relations, optica l identifications and source variability.