Muzzin, Adam and Wilson, Gillian and Yee, H. K. C. and Gilbank, David and Hoekstra, Henk and Demarco, Ricardo and Balogh, Michael and van Dokkum, Pieter and Franx, Marijn and Ellingson, Erica and Hicks, Amalia and Nantais, Julie and Noble, Allison and Lacy, Mark and Lidman, Chris and Rettura, Alessandro and Surace, Jason and Webb, Tracy (2012) The Gemini Cluster Astrophysics Spectroscopic Survey (GCLASS): The Role of Environment and Self-regulation in Galaxy Evolution at z ~ 1. Astrophysical Journal, 746 (2). Art. No. 188. ISSN 0004-637X http://resolver.caltech.edu/CaltechAUTHORS:20120327-145849890
- Published Version
See Usage Policy.
Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20120327-145849890
We evaluate the effects of environment and stellar mass on galaxy properties at 0.85 <z < 1.20 using a 3.6 μm-selected spectroscopic sample of 797 cluster and field galaxies drawn from the Gemini Cluster Astrophysics Spectroscopic Survey. We confirm that for galaxies with log M_*/M_☉ > 9.3 the well-known correlations between environment and properties such as star-forming fraction (f SF), star formation rate (SFR), specific SFR (SSFR), D_n (4000), and color are already in place at z ~ 1. We separate the effects of environment and stellar mass on galaxies by comparing the properties of star-forming and quiescent galaxies at fixed environment and fixed stellar mass. The SSFR of star-forming galaxies at fixed environment is correlated with stellar mass; however, at fixed stellar mass it is independent of environment. The same trend exists for the D_n (4000) measures of both the star-forming and quiescent galaxies and shows that their properties are determined primarily by their stellar mass, not by their environment. Instead, it appears that environment's primary role is to control the fraction of star-forming galaxies. Using the spectra we identify candidate poststarburst galaxies and find that those with 9.3 < log M_*/M_☉ < 10.7 are 3.1 ± 1.1 times more common in high-density regions compared to low-density regions. The clear association of poststarbursts with high-density regions as well as the lack of a correlation between the SSFRs and D_n (4000)s of star-forming galaxies with their environment strongly suggests that at z ~ 1 the environmental-quenching timescale must be rapid. Lastly, we construct a simple quenching model which demonstrates that the lack of a correlation between the D_n (4000) of quiescent galaxies and their environment results naturally if self quenching dominates over environmental quenching at z > 1, or if the evolution of the self-quenching rate mirrors the evolution of the environmental-quenching rate at z > 1, regardless of which dominates.
|Additional Information:||© 2012 American Astronomical Society. Received 2011 October 6; accepted 2011 December 14; published 2012 February 6. The GCLASS project is the result of a generous investment in observing time from both the Canadian and U.S. Gemini partners. The GCLASS data were taken in eight separate allocations over the period of 2007–2010 and we thank members of both Can-TAC and NOAO-TAC for their continued long-term support of the project. GCLASS would also not have been possible without the hard work of members of the Gemini staff, who carefully checked the many mask designs, phase2 skeletons, and overall ensured the delivery of high-quality data products. We acknowledge all members of the Gemini staff who have been involved in executing the GCLASS observations. G.W. gratefully acknowledges support from NSF grant AST-0909198.|
|Subject Keywords:||galaxies: clusters: general; galaxies: evolution; galaxies: formation; galaxies: high-redshift|
|Official Citation:||The Gemini Cluster Astrophysics Spectroscopic Survey (GCLASS): The Role of Environment and Self-regulation in Galaxy Evolution at z ~ 1 Adam Muzzin et al. 2012 ApJ 746 188|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Ruth Sustaita|
|Deposited On:||27 Mar 2012 22:20|
|Last Modified:||26 Dec 2012 14:59|
Repository Staff Only: item control page