A Detailed Study of Massive Galaxies in a Protocluster at z = 3.13
A Detailed Study of Massive Galaxies in a Protocluster at z = 3.13
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DOI：
10.3847/1538-4357/aba626
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发表时间：
2020-07
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影响因子：
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通讯作者：
Ke Shi;J. Toshikawa;Z. Cai;Kyoung-soo Lee;T. Fang
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作者：
Ke Shi;J. Toshikawa;Z. Cai;Kyoung-soo Lee;T. Fang
我们在z = 3.13的原星团场中对近红外选择的星系进行了详细的研究。利用现有的多波长数据选择原星系团，光度红移（photo-z）在2.9 < z < 3.3，达到质量完备性。在这个领域已经发现了不同类型的星系，包括正常的恒星形成星系，静止的星系和尘埃恒星形成星系。photoz星系在场中形成了两个大的超密结构，与之前分别由Lyα发射体（LAEs）和Lyman破星系追踪到的星系超密结构在很大程度上重叠。北部的过度密度由很大一部分古老和/或尘埃星系群组成，而南部的过度密度主要由与lae空间相关的正常恒星形成星系组成。这与我们之前的研究一致，认为不同星系过密度的空间偏移可能是由于光晕组合偏差。考虑到这两个超密度星系端到端的大尺寸，一种可能性是，到目前为止，它们将形成一个超星团。我们还发现了强有力的证据，表明在密度过大的原星团区域的星系的恒星形成活动比在野外的星系强，这表明在这个原星团中加速了质量聚集。
We present a detailed study of near-IR selected galaxies in a protocluster field at z = 3.13. Protocluster galaxies are selected using the available mutliwavelength data with the photometric redshifts (photo-z) at 2.9 < z < 3.3, reaching a mass completeness of . Diverse types of galaxies have been found in the field, including normal star-forming galaxies, quiescent galaxies, and dusty star-forming galaxies. The photo-z galaxies form two large overdense structures in the field, largely overlapping with the previously identified galaxy overdensities traced by Lyα emitters (LAEs) and Lyman break galaxies, respectively. The northern overdensity consists of a large fraction of old and/or dusty galaxy populations, while the southern one is mainly composed of normal star-forming galaxies that are spatially correlated with the LAEs. This agrees with our previous study arguing the spatial offset of different galaxy overdensities may be due to halo assembly bias. Given the large end-to-end sizes of the two overdensities, one possibility is that they will form into a supercluster by the present day. We also find strong evidence that the star formation activities of the galaxies in the overdense protocluster regions are enhanced in comparison to their field counterparts, which suggests an accelerated mass assembly in this protocluster.