The Southern SHARC catalogue: a ROSAT survey for distant galaxy clusters

X-ray selection provides a way of creating well-defined samples of distant clusters free from projection effects and with a well-understood selection function. This paper describes the creation of one such catalogue - the Southern Serendipitous High-redshift Archival ROSAT Cluster (SHARC) survey - which covers an area of 17.7 deg² and consists of 32 clusters with redshifts between 0.05 and 0.7 and X-ray luminosities between 7 × 10⁴² and 4 × 10⁴⁴ erg s^-1: the high-redshift subsample contains 16 clusters with z>= 0.3 and X-ray luminosities greater than 2 × 10⁴³ erg s^-1 (luminosities are quoted for the 0.5-2.0 keV energy band). The catalogue is in good agreement with those of other ROSAT cluster surveys for those fields in common. The high-redshift sample is consistent with there being no evolution in the cluster X-ray luminosity function at luminosities ~10⁴⁴ erg s^-1: the implications of this work have been described elsewhere.