(1) We have correlated the 116 417 X-ray sources detected in the RASS II processing with a sample of 14 315 galaxies selected from the IRAS PSC. Our results build upon a previous correlation of these IRAS galaxies with the RASS I processing.
(2) 372 IRAS galaxies show X-ray emission within a distance of 100 arcsec from the infrared position.
(3) X-ray contour plots overlaid on Palomar Digitized Sky Survey images were inspected to quantify the likelihood that the X-rays originate from the IRAS galaxy. These images are shown for each of the 372 potential identifications.
(4) For 197 objects the soft X-ray emission is very likely associated with the IRAS galaxy. For these objects the soft X-ray fluxes and luminosities are computed and compared with their far-infrared emission. For 42 objects with more than 100 detected source photons we were able to improve the flux estimates by fitting power-law spectra with free spectral index and free absorption column density.
(5) The ratio between the soft X-ray and the far-infrared flux covers about 4 order of magnitudes and can reach values above unity.
Acknowledgements
We thank J. Trümper, W. Pietsch and U. Zimmermann for helpful discussions. We thank A. Vogler for the help in producing the images with overlayed X-ray contours. We thank the referee, Dr. M. Lehnert for his suggestions to further improve the paper. The ROSAT project is supported by the Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie (BMBF/DARA) and the Max-Planck-Society. FB acknowledges support by the Deutsche Forschungsgemeinschaft.