Evolutionary Phases of Gas-rich Galaxies in a Galaxy Cluster at z = 1.46
Evolutionary Phases of Gas-rich Galaxies in a Galaxy Cluster at z = 1.46
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DOI：
10.3847/2041-8213/aa71ad
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发表时间：
2017-05
期刊：
影响因子：
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通讯作者：
M. Hayashi;T. Kodama;K. Kohno;Y. Yamaguchi;K. Tadaki;B. Hatsukade;Y. Koyama;R. Shimakawa;Y. Tamura;Tomoko L. Suzuki
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文献类型：
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作者：
M. Hayashi;T. Kodama;K. Kohno;Y. Yamaguchi;K. Tadaki;B. Hatsukade;Y. Koyama;R. Shimakawa;Y. Tamura;Tomoko L. Suzuki
我们报告了对 XMMXCS J2215.9–1738 星团 z = 1.46 处星系中分子气体的调查。在阿塔卡马大型毫米/亚毫米阵列的波段3数据中，我们在距星团中心R200半径范围内检测到了17个星系的发射线，频率覆盖范围为93-95 GHz，空间方向覆盖范围为2.33 arcmin2。这些谱线均通过其红移以及光学和近红外 (NIR) 对应物的颜色被识别为来自星团成员的 CO J = 2–1 发射谱线。线光度低至 K km s−1 pc2。 CO(2-1) 探测到的星系空间分布表明它们从星团的正中心消失。显示相对速度与星团中心距离的相空间图表明，富含气体的星系比贫气体的恒星形成星系和位于该星团维里化区域的被动星系更晚进入该星团。结果表明，星系在向星团中心坠落的过程中经历了冲压压力剥离和/或绞杀，然后星团中心星系中的分子气体因恒星形成而耗尽。
We report a survey of molecular gas in galaxies in the XMMXCS J2215.9–1738 cluster at z = 1.46. We have detected emission lines from 17 galaxies within a radius of R200 from the cluster center, in Band 3 data of the Atacama Large Millimeter/submillimeter Array, with a coverage of 93–95 GHz in frequency and 2.33 arcmin2 in spatial direction. The lines are all identified as CO J = 2–1 emission lines from cluster members at by their redshifts and the colors of their optical and near-infrared (NIR) counterparts. The line luminosities reach down to K km s−1 pc2. The spatial distribution of galaxies with a detection of CO(2–1) suggests that they disappear from the very center of the cluster. The phase-space diagram showing relative velocity versus cluster-centric distance indicates that the gas-rich galaxies have entered the cluster more recently than the gas-poor star-forming galaxies and passive galaxies located in the virialized region of this cluster. The results imply that the galaxies experienced ram-pressure stripping and/or strangulation during the course of infall toward the cluster center and then the molecular gas in the galaxies at the cluster center was depleted by star formation.