Early-type galaxies at z ~ 1.3. III. On the dependence of formation epochs and star formation histories on stellar mass and environment

From National Research Council Canada

DOI	Resolve DOI: https://doi.org/10.1088/0004-637X/732/2/94
Author	Search for: Rettura, A.; Search for: Mei, S.; Search for: Stanford, S. A.; Search for: Raichoor, A.; Search for: Moran, S.; Search for: Holden, B.; Search for: Rosati, P.; Search for: Ellis, R.; Search for: Nakata, F.; Search for: Nonino, M.; Search for: Treu, T.; Search for: Blakeslee, J. P.¹; Search for: Demarco, R.; Search for: Eisenhardt, P.; Search for: Ford, H. C.; Search for: Fosbury, R. A. E.; Search for: Illingworth, G.; Search for: Huertas-Company, M.; Search for: Jee, M. J.; Search for: Kodama, T.; Search for: Postman, M.; Search for: Tanaka, M.; Search for: White, R. L.
Affiliation	National Research Council of Canada. NRC Herzberg Institute of Astrophysics
Format	Text, Article
Subject	cosmology: observations; galaxies: clusters: general; galaxies: elliptical and lenticular, cD; galaxies: evolution; galaxies: formation; galaxies: star formation
Abstract	We study the environmental dependence of stellar population properties at z similar to 1.3. We derive galaxy properties (stellar masses, ages, and star formation histories) for samples of massive, red, passive early-type galaxies (ETGs) in two high-redshift clusters, RXJ0849+4452 and RXJ0848+4453 (with redshifts of z = 1.26 and 1.27, respectively), and compare them with those measured for the RDCS1252.9-2927 cluster at z = 1.24 and with those measured for a similarly mass-selected sample of field contemporaries drawn from the GOODS-South field. Robust estimates of the aforementioned parameters have been obtained by comparing a large grid of composite stellar population models with extensive 8- to 10-band photometric coverage, from the rest-frame far-ultraviolet to the infrared. We find no variations of the overall stellar population properties among the different samples of cluster ETGs. However, when comparing cluster versus field stellar population properties we find that, even if the ages are similar and depend only on galaxy mass, the ones in the field do employ longer timescales to assemble their final mass. We find that, approximately 1Gyr after the onset of star formation, the majority (75%) of cluster galaxies have already assembled most (> 80%) of their final mass, while, by the same time, fewer (35%) field ETGs have. Thus, we conclude that while galaxy mass regulates the timing of galaxy formation, the environment regulates the timescale of their star formation histories.
Publication date	2011-05-10
Publisher	American Astronomical Society IOP Publishing
In	The Astrophysical Journal 732, no. 2, 94.
Language	English
Peer reviewed	Yes
NPARC number	19770575
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Record identifier	cbc631b6-7f51-4da1-bbb0-915b6df737ac
Record created	2012-04-04
Record modified	2020-04-21

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