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外文期刊>The Astrophysical journal
>THE GEMINI CLUSTER ASTROPHYSICS SPECTROSCOPIC SURVEY (GCLASS): THE ROLE OF ENVIRONMENT AND SELF-REGULATION IN GALAXY EVOLUTION AT z ～ 1*
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THE GEMINI CLUSTER ASTROPHYSICS SPECTROSCOPIC SURVEY (GCLASS): THE ROLE OF ENVIRONMENT AND SELF-REGULATION IN GALAXY EVOLUTION AT z ～ 1*
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.
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机译：我们使用从双子星团天体物理学光谱调查中提取的797个星团和场星系的3.6μm选择光谱样本，评估了环境和恒星质量对星系性质在0.85 9.3的星系，环境与属性之间的众所周知的相关性，例如恒星形成率（f SF），恒星形成率（SFR），比SFR（SSFR），D n （4000），并且在z〜1处已经存在颜色。我们通过比较固定环境和固定恒星质量下恒星形成和静态星系的性质，来区分环境和恒星质量对星系的影响。恒星形成星系在固定环境下的SSFR与恒星质量相关。但是，在恒星质量固定的情况下，它与环境无关。对于形成恒星和静止星系的D n（4000）量度，存在相同的趋势，这表明它们的性质主要由恒星质量决定，而不是由环境决定。相反，环境的主要作用似乎是控制恒星形成星系的比例。利用光谱，我们确定了星爆后星系的候选星系，发现与高密度地区相比，高密度地区9.3 1时自猝灭胜于环境猝灭，或者如果自我进化，则静止星系的D n（4000）与周围环境之间缺乏相关性自然而然猝灭速率反映了z> 1时环境猝灭速率的变化，而不管哪个占主导地位。
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