ROSAT PSPC observations of nearby spiral galaxies -- I. The data

Abstract

We report here the results of the largest detailed X-ray survey of nearby spiral galaxies performed with the ROSAT Position Sensitive Proportional Counter (PSPC) to date — a uniform analysis of a sample of 17 systems covering a wide range in activity and inclination. This study provides a significant advance over earlier pioneering work performed with Einstein. We have attempted, for each system, to separate the point-source emission from the diffuse emission, allowing an insight into the properties of X-ray sources within external galaxies, and enabling us to establish the prevalence and properties of hot galactic winds and haloes. The X-ray properties of both the point-source emission and the diffuse emission within each of the 17 systems are discussed in detail, as are the general X-ray properties of the whole survey. We also derive physical parameters for the hot gas observed within many of these systems. A forthcoming paper will use the results presented here to analyse the statistical properties of the sample as a whole.