The HI Mass Function in Ursa Major

A deep blind HI survey of the nearby spiral-rich Ursa Major Cluster has been performed with the VLA in parallel with a wide-field R-band imaging campaign of most VLA fields with the CFHT. The goal is to measure the slope of the HI mass function (HIMF) down to HI masses of 107 Msolar as well as the slope of the faint-end of the luminosity function (LF) down to M(R)=-10. The VLA survey sampled 16% of the Ursa Major Cluster volume. Both the HIMF and the LF in Ursa Major are nearly flat at their faint ends. No free-floating HI clouds were detected