Multiwavelength observations of the field HS 47.5/22 in Ursa Major ^*,**

I. The X–ray catalogue of a medium deep ROSAT survey

¹ Hamburger Sternwarte, Gojenbergsweg 112, D–21029 Hamburg, Germany
² Max–Planck–Institut für extraterrestrische Physik, D–85740 Garching, Germany

Send offprint request to: K. Molthagen

Received: 10 March 1997
Accepted: 17 April 1997

Abstract

We present the X–ray source catalogue obtained from a ROSAT survey in the HQS field HS 47.5/22. The survey consists of 48 overlapping PSPC pointings which were first analysed individually, and then merged to increase the sensitivity. Both modes bring forth sources missed in the other, showing that both are necessary to detect all X–ray sources in the field. The final catalogue contains 574 X–ray sources. The identifications are mainly based on the HQS objective prism plate which allows object classification down to a magnitude , and a rough distinction between red and blue objects more than a magnitude deeper. Follow–up observations were performed for a number of objects, mainly faint quasar candidates.