Mining for normal galaxies in the first XMM–Newton Serendipitous Source Catalog

This paper uses the first XMM-Newton Serendipitous Source Catalog compiled by the XMM-Newton Science Centre to identify low-z X-ray selected normal galaxy candidates. Our sample covers a total area of ≈6 deg 2 to the 0.5-2 ke V limit ≈10 -15 erg s -1 cm -2 . A total of 23 sources are selected on the basis of low X-ray to optical flux ratio log f X /f opt 10 42 erg s -1 .