UV observations of the galaxy cluster Abell 1795 with the optical monitor on XMM-Newton

We present the results of an analysis of broad band UV observations of the central regions of Abell 1795 observed with the optical monitor on XMM-Newt on. As have been found with other UV observations of the central regions of clusters of galaxies, we find evidence for star formation. However, we als o find evidence for absorption in the cD galaxy on a more extended scale th an has been seen with optical imaging. We also report the first UV observat ion of part of the filamentary structure seen in H alpha, X-rays and very d eep U band imaging. The part of the filament we see is very blue with UV co lours consistent with a very early (O/B) stellar population. This is the fi rst direct evidence of a dominant population of early type stars at the cen tre of Abell 1795 and implies very recent star formation at the centre of t his cluster.