A Planck-selected dusty proto-cluster at z=2.16 associated with a strong over-density of massive H$alpha$ emitting galaxies. (arXiv:2008.13614v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Koyama_Y/0/1/0/all/0/1">Yusei Koyama</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Polletta_M/0/1/0/all/0/1">Maria del Carmen Polletta</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tanaka_I/0/1/0/all/0/1">Ichi Tanaka</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kodama_T/0/1/0/all/0/1">Tadayuki Kodama</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dole_H/0/1/0/all/0/1">Hervé Dole</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Soucail_G/0/1/0/all/0/1">Geneviève Soucail</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Frye_B/0/1/0/all/0/1">Brenda Frye</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lehnert_M/0/1/0/all/0/1">Matt Lehnert</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Scodeggio_M/0/1/0/all/0/1">Marco Scodeggio</a>
We discovered an over-density of H-alpha-emitting galaxies associated with a
Planck compact source in the COSMOS field (PHzG237.0+42.5) through narrow-band
imaging observations with Subaru/MOIRCS. This Planck-selected dusty
proto-cluster at z=2.16 has 38 H-alpha emitters including six spectroscopically
confirmed galaxies in the observed MOIRCS 4’x7′ field (corresponding to
~2.0×3.5~Mpc^2). We find that massive H-alpha emitters with log(M*/Msun)>10.5
are strongly clustered in the core of the proto-cluster (within ~300-kpc from
the density peak of the H-alpha emitters). Most of the H-alpha emitters in this
proto-cluster lie along the star-forming main sequence using H-alpha-based SFR
estimates, whilst the cluster total SFR derived by integrating the
H-alpha-based SFRs is an order of magnitude smaller than those estimated from
Planck/Herschel FIR photometry. Our results suggest that H-alpha is a good
observable for detecting moderately star-forming galaxies and tracing the
large-scale environment in and around high-z dusty proto-clusters, but there is
a possibility that a large fraction of star formation could be obscured by dust
and undetected in H-alpha observations.
We discovered an over-density of H-alpha-emitting galaxies associated with a
Planck compact source in the COSMOS field (PHzG237.0+42.5) through narrow-band
imaging observations with Subaru/MOIRCS. This Planck-selected dusty
proto-cluster at z=2.16 has 38 H-alpha emitters including six spectroscopically
confirmed galaxies in the observed MOIRCS 4’x7′ field (corresponding to
~2.0×3.5~Mpc^2). We find that massive H-alpha emitters with log(M*/Msun)>10.5
are strongly clustered in the core of the proto-cluster (within ~300-kpc from
the density peak of the H-alpha emitters). Most of the H-alpha emitters in this
proto-cluster lie along the star-forming main sequence using H-alpha-based SFR
estimates, whilst the cluster total SFR derived by integrating the
H-alpha-based SFRs is an order of magnitude smaller than those estimated from
Planck/Herschel FIR photometry. Our results suggest that H-alpha is a good
observable for detecting moderately star-forming galaxies and tracing the
large-scale environment in and around high-z dusty proto-clusters, but there is
a possibility that a large fraction of star formation could be obscured by dust
and undetected in H-alpha observations.
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