The Local Cluster Survey. I. Evidence of Outside-in Quenching in Dense Environments
The Local Cluster Survey. I. Evidence of Outside-in Quenching in Dense Environments
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DOI：
10.3847/1538-4357/aac32a
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发表时间：
2018-07
期刊：
影响因子：
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通讯作者：
R. Finn;V. Desai;G. Rudnick;M. Balogh;M. Haynes;P. Jablonka;R. Koopmann;J. Moustakas;C. Peng;B. Poggianti;K. Rines;D. Zaritsky
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文献类型：
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作者：
R. Finn;V. Desai;G. Rudnick;M. Balogh;M. Haynes;P. Jablonka;R. Koopmann;J. Moustakas;C. Peng;B. Poggianti;K. Rines;D. Zaritsky
本地星团调查的目标是在附近的星系团和星团中寻找环境驱动的恒星形成星系熄灭的证据。猝灭与环境和恒星质量有关，目前许多观测证据来自星系的综合特性。然而，恒星和恒星形成盘的相对大小对环境处理很敏感，可以帮助确定导致致密环境中大部分星系淬灭的机制。为此，我们利用斯皮策太空望远镜的24 μm成像，测量了9个星系群和星团（0.02 0.1 M⊙yr−1）中224个星系的恒星形成盘的大小。我们用星盘的大小（Rd）归一化了24 μm的有效半径（R24）。我们发现，具有较高膨胀-总比（B/T）的恒星形成星系和在更密集环境中的星系具有更集中的恒星形成。与H质量分数和NUV -r颜色的比较表明，星系从富含气体和蓝色到耗尽和红色的转变伴随着恒星形成中心浓度的增加。我们建立了一个简单的模型来限制星团环境中恒星形成盘收缩的时间尺度。我们的结果与长时间尺度（bbbb2gyr）机制一致，该机制产生由外而内的淬火，例如去除扩展的气晕或冷盘气体的弱剥离。
The goal of the Local Cluster Survey is to look for evidence of environmentally driven quenching among star-forming galaxies in nearby galaxy groups and clusters. Quenching is linked with environment and stellar mass, and much of the current observational evidence comes from the integrated properties of galaxies. However, the relative size of the stellar and star-forming disk is sensitive to environmental processing and can help identify the mechanisms that lead to a large fraction of quenched galaxies in dense environments. Toward this end, we measure the size of the star-forming disks for 224 galaxies in nine groups and clusters (0.02 0.1 M⊙ yr−1) using 24 μm imaging from the Spitzer Space Telescope. We normalize the 24 μm effective radius (R24) by the size of the stellar disk (Rd). We find that star-forming galaxies with higher bulge-to-total ratios (B/T) and galaxies in more dense environments have more centrally concentrated star formation. Comparison with H i mass fractions and NUV − r colors indicates that a galaxy’s transition from gas-rich and blue to depleted and red is accompanied by an increase in the central concentration of star formation. We build a simple model to constrain the timescale over which the star-forming disks shrink in the cluster environment. Our results are consistent with a long-timescale (>2 Gyr) mechanism that produces outside-in quenching, such as the removal of the extended gas halo or weak stripping of the cold disk gas.