THE DEPENDENCE OF STAR FORMATION RATES ON STELLAR MASS AND ENVIRONMENT AT z approx 0.8

Journal Article · Sun Nov 01 04:00:00 EST 2009 · Astrophysical Journal (Online)

DOI:https://doi.org/10.1088/0004-637X/705/1/L67· OSTI ID:21378365

Patel, Shannon G; Holden, Bradford P; Illingworth, Garth D ^[1]; Kelson, Daniel D ^[2]; Franx, Marijn ^[3]

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1. UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States)
2. Observatories of the Carnegie Institution of Washington, Pasadena, CA 91101 (United States)
3. Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 AA Leiden (Netherlands)

We examine the star formation rates (SFRs) of galaxies in a redshift slice encompassing the z = 0.834 cluster RX J0152.7 - 1357. We used a low-dispersion prism in the Inamori Magellan Areal Camera and Spectrograph to identify galaxies with z {sub AB} < 23.3 mag in diverse environments around the cluster out to projected distances of approx8 Mpc from the cluster center. We utilize a mass-limited sample (M > 2 x 10{sup 10} M{sub sun}) of 330 galaxies that were imaged by Spitzer MIPS at 24 mum to derive SFRs and study the dependence of specific SFR (SSFR) on stellar mass and environment. We find that the SFR and SSFR show a strong decrease with increasing local density, similar to the relation at z approx 0. Our result contrasts with other work at z approx 1 that finds the SFR-density trend to reverse for luminosity-limited samples. These other results appear to be driven by star formation (SF) in lower mass systems (M approx 10{sup 10} M{sub sun}). Our results imply that the processes that shut down SF are present in groups and other dense regions in the field. Our data also suggest that the lower SFRs of galaxies in higher density environments may reflect a change in the ratio of star-forming to non-star-forming galaxies, rather than a change in SFRs. As a consequence, the SFRs of star-forming galaxies, in environments ranging from small groups to clusters, appear to be similar and largely unaffected by the local processes that truncate SF at z approx 0.8.

• OSTI ID: 21378365
• Journal Information: Astrophysical Journal (Online), Journal Name: Astrophysical Journal (Online) Journal Issue: 1 Vol. 705; ISSN 1538-4357
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
EVOLUTION
GALACTIC EVOLUTION
GALAXIES
GALAXY CLUSTERS
LUMINOSITY
MASS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RED SHIFT
STARS