GBT25A-102

Further HI Observations of Giant Low Surface Brightness Galaxies

Abstract

Giant low surface brightness galaxies (gLSBs) are galaxies that have extended, optically faint disks as well as a high total mass. In the standard hierarchical merging paradigm galaxies this large would have undergone several major mergers to reach such a large mass. However such major mergers would have likely destroyed the extended disks that these galaxies are observed to have. Thus understanding how these massive galaxies retain such large disks is a critical test of galaxy formation models. The identification of gLSB is often based on their high HI mass. What we have been doing is observing gLSBs selected from deep optical imaging to remove any bias towards the HI properties of the galaxies. Already in our pilot sample we have one gLSB that has significantly lower HI mass than the other gLSBs. Additionally we have found in our pilot sample that gLSBs are more likely to have asymmetric HI profiles than other galaxies. In this proposal we are asking for Greenbank Telescope (GBT) time to expand our pilot program to observe the HI spectrum of another 11 gLSBs. With this expanded sample we can better determine the formation scenarios for these extreme galaxies.

Investigators

Name	Institution
Philip Lah *	Abu Dhabi, New York University
Joseph Gelfand	New York University; National Science Foundation ; Abu Dhabi, New York University
Ivan Katkov	Abu Dhabi, New York University

* indicates the PI