The second epoch Molonglo Galactic Plane Survey: Compact source catalogue

Abstract

We present the first data release from the second epoch Molonglo Galactic Plane Survey (MGPS-2). MGPS-2 was carried out with the Molonglo Observatory Synthesis Telescope at a frequency of 843 MHz and with a restoring beam of 45 x 45 csc|δ| arcsec2, making it the highest resolution large-scale radio survey of the southern Galactic plane. It covers the range |b| < 10° and 245° < l < 365°, and is the Galactic counterpart to the Sydney University Molonglo Sky Survey (SUMSS) which covers the whole southern sky with δ ≤ -30° (|b| > 10°). In this paper, we present the MGPS-2 compact source catalogue. The catalogue has 48 850 sources above a limiting peak brightness of 10 mJy beam-1. Positions in the catalogue are accurate to 1-2 arcsec. A full catalogue including extended sources is in preparation. We have carried out an analysis of the compact source density across the Galactic plane and find that the source density is not statistically higher than the density expected from the extragalactic source density alone. We also present version 2.0 of the SUMSS image data and catalogue which is now available online. The data consist of 629 4.3° x 4.3° mosaic images covering the 8100 deg2 of sky with δ ≤ -30° and |b| > 10°. The catalogue contains 210 412 radio sources to a limiting peak brightness of 6 mJy beam-1 at δ ≤ -50° and 10 mJy beam-1 at δ > -50°. We describe the updates and improvements made to the SUMSS cataloguing process. © 2007 The Authors.