NOAO >   Observing Info >   Approved Programs >   2008A-0556

Small NOAO Logo

Proposal Information for 2008A-0556


PI: Ronald Marzke, San Francisco State University, marzke@sfsu.edu
Address: Physics Department, 1600 Holloway Ave., San Francisco, CA 94132, United States

CoI: Mike Hudson, University of Waterloo
CoI: Brent Tully, University of Hawaii

Title: The Faint End of the Galaxy Luminosity Function: Efficient Photometric Selection of Faint Spectroscopic Targets in the Coma Cluster

Abstract: We propose deep, eight-filter imaging of the Coma cluster core to select a sample of candidate cluster members to r=23.5 for spectroscopic followup with Keck/LRIS. The filter set includes intermediate-band filters from the BATC set in the UV and blue to provide better sensitivity to the 4000Abreak at redshifts less than 0.1. The resulting photometric redshifts allow an order of magnitude reduction in background contamination of faint spectroscopic samples. These observations support an ongoing HST/ACS Treasury survey of the Coma cluster and will be used to measure the faint end of the Coma cluster luminosity function to M_r=-11.5. Our goal is to measure the luminosity function without resorting to statistical background subtraction and to lay the groundwork for future spectroscopic surveys of poorer systems, where background contamination is even more severe. Despite poor weather during the nights allocated to this program in 2007A (0.5/4 photometric), we were able to confirm the effectiveness of this technique by combining the much shallower imaging we did obtain (to r~22) with 791 redshifts measured in 2007A with MMT/Hectospec.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2008A-0556

noaoprop-help@noao.edu

Small NOAO Logo