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Massive starburst galaxies in a z = 2.16 proto-cluster unveiled by panoramic Hα mapping

Koyama, Y.; Kodama, T.; Tadaki, K.-i; Hayashi, M.; Tanaka, M.; Smail, I.; Tanaka, I.; Kurk, J.

Massive starburst galaxies in a z = 2.16 proto-cluster unveiled by panoramic Hα mapping Thumbnail


Authors

Y. Koyama

T. Kodama

K.-i Tadaki

M. Hayashi

M. Tanaka

I. Tanaka

J. Kurk



Abstract

We present a panoramic narrow-band study of Hα emitters in the field of the z = 2.16 proto-cluster around PKS 1138−262 using MOIRCS on the Subaru Telescope. We find 83 Hα emitters down to a star formation rate of SFR (Hα) ∼ 10 M⊙ yr−1 across a ∼ 7 × 7 arcmin2 region centred on the radio galaxy, and identify ∼10-Mpc scale filaments of emitters running across this region. By examining the properties of Hα emitters within the large-scale structure, we find that galaxies in the higher density environments at z = 2.16 tend to have redder colours and higher stellar masses compared to galaxies in more underdense regions. We also find a population of Hα emitters with red colours [(J − Ks) ≳ 1], which are much more frequent in the denser environments and which have apparently very high stellar masses with M* ≳ 1011 M⊙, implying that these cluster galaxies have already formed a large part of their stellar mass before z ∼ 2. Spitzer Space Telescope 24-μm data suggest that many of these red Hα emitters are bright, dusty starbursts (rather than quiescent sources). We also find that the proto-cluster galaxies follow the same correlation between SFR and M* (the ‘main sequence’) of z ∼ 2 field star-forming galaxies, but with an excess of massive galaxies. These very massive star-forming galaxies are not seen in our similar, previous study of z ∼ 1 clusters, suggesting that their star formation activity has been shut off at 1 ≲ z ≲ 2. We infer that the massive red (but active) galaxies in this rich proto-cluster are likely to be the products of environmental effects, and they represent the accelerated galaxy formation and evolution in a biased high-density region in the early Universe.

Citation

Koyama, Y., Kodama, T., Tadaki, K., Hayashi, M., Tanaka, M., Smail, I., …Kurk, J. (2013). Massive starburst galaxies in a z = 2.16 proto-cluster unveiled by panoramic Hα mapping. Monthly Notices of the Royal Astronomical Society, 428(2), 1551-1564. https://doi.org/10.1093/mnras/sts133

Journal Article Type Article
Publication Date Jan 1, 2013
Deposit Date May 10, 2013
Publicly Available Date Mar 28, 2024
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Electronic ISSN 1365-2966
Publisher Royal Astronomical Society
Peer Reviewed Peer Reviewed
Volume 428
Issue 2
Pages 1551-1564
DOI https://doi.org/10.1093/mnras/sts133
Keywords Galaxies: clusters: individual: PKS 1138−262, Galaxies: evolution, Large-scale structure of Universe

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Copyright Statement
This article has been accepted for publication in Monthly notices of the Royal Astronomical Society © 2013 The Authors Published by Oxford University Press on behalf of Royal Astronomical Society. All rights reserved.





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