8734( 1) - 12/30/99 13:00 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8734 Version: 1 Check-in Date: 30-Dec-1999 12:30:42 1.Proposal Title: Star Formation in E+A Galaxies in Distant Clusters ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle AR 9 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: James Rose University of North Carolina CoI: Ms. Lindsay Bartholomew University of North Carolina N CoI: Mr. Alejandro Gaba University of North Carolina N CoI: Dr. Nelson Caldwell F. L. Whipple Observatory, Smithsonian N Institution ------------------------------------------------------------------------------------ 5. Abstract It is well-known that star formation occurs at a substantially higher level in galaxies in distant rich clusters (z>0.3) than it does in their nearby cluster counterparts. A much- contested issue is what environmental effect leads to the termination of star formation between z=0.3 and the present epoch. For instance, there is considerable controversy regarding whether disk star formation in cluster spirals is simply truncated, perhaps by ram pressure stripping, or whether the gas is depleted by a major starburst. We propose to carry out surface photometry of 63 ``E+A'' galaxies in four distant clusters, and of a similar number of galaxies with ``normal'' spectra, using two-color WFPC2 imaging of these clusters. The goal is to see whether the E+A galaxies have bluer nuclei than the surrounding disk, which would indicate the presence of a recent starburst, as opposed to truncated star formation in the disk. We have already searched the HST archive of distant cluster images, and located two-color images of these 63 E+A galaxies. We now request funding to carry out the surface photometry and color maps, so that we can distinguish between the two hypotheses for the end of star formation in distant clusters. ------------------------------------------------------------------------------------ 8734( 1) - 12/30/99 13:00 - [ 2] Summary Form for Proposal 8734 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category AR ------------------------------------------------------------------------------------------------------------------------------------