The ROSAT Wide Field Camera all-sky survey of extreme-ultraviolet sources — The 2RE source catalogue

Abstract

During 1990-91 the Wide Field Camera (WFC), on the ROSAT satellite, performed the first allsky survey at EUV wavelengths. The survey was conducted in two wavebands, S1 and S2, with passbands covering the ranges 60–140 Å and 110–200 Å. It was fully imaging, with effective spatial resolution of about 3 arcmin FWHM, and point source location accuracy of typically better than 1 arcmin. An initial analysis produced a published Bright Source Catalogue (BSC) of 383 sources. Of those optically identified in the BSC, 181 were found to be late-type stars, 119 hot DA white dwarfs, 17 CVs and 7 AGNs. Recently the database has been completely reprocessed to take advantage of several significant developments over what was possible during the course of the BSC work. Compared to the BSC, this has increased (i) the number of EUV sources by ∼ 25% and (ii) the number of detection pairs, ie. sources seen in both wavebands, from ∼ 60% to ∼ 80%. We describe the contents of the new “2RE” catalogue in terms of sky exposure, optical identifications, source counts and time-series analysis. Further, we outline our plans for a public archive of these data.