NOAO >   Observing Info >   Approved Programs >   2009B-0118

Small NOAO Logo

Proposal Information for 2009B-0118


PI: Rose Finn, Siena College, rfinn@siena.edu
Address: Physics Department, 515 Loudon Rd, Loudonville, NY 12211, USA

CoI: Ken Rines, Western Washington University
CoI: Janice Lee, Carnegie
CoI: Daniel Dale, University of Wyoming
CoI: Dennis Zaritsky, University of Arizona

Title: H(alpha) Narrow-band Imaging of z ~ 0.8 Galaxy Clusters

Abstract: We request 2 nights of 4.0-m time to complete narrow-band imaging centered on the observed wavelength of \ha for two z=0.8 galaxy clusters using NEWFIRM and a custom narrow-band filter. A third cluster will be targeted during 2010A. The narrow-band filter is designed to sample a region of the IR window that is relatively free from OH emission; we are thus able to detect low star-formation rates (SFRs) (2 \smy) in a reasonable amount of observing time. NEWFIRM's large field- of-view allows simultaneous imaging of the cluster center and surrounding infall region, an area where galaxy transformation is likely taking place. These data, in conjunction with a companion survey of z=0.8 field galaxies led by CoI Lee, will provide a census of SFRs over the full range in galactic environments at an epoch when the Universe was half its current age. In contrast, most field surveys of intermediate-redshift galaxies deliberately avoid clusters and thus fail to survey the densest galactic environments. The z=0.8 epoch probes a cosmologically interesting time in cluster evolution, when clusters were only half their present mass and accretion rates were higher. This study is thus uniquely suited to determine whether clusters speed a galaxy's evolution from star-forming to quiescent.


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 >   2009B-0118

noaoprop-help@noao.edu

Small NOAO Logo