TY - JOUR
T1 - MAHALO Deep Cluster Survey II. Characterizing massive forming galaxies in the Spiderweb protocluster at z = 2.2
AU - Shimakawa, Rhythm
AU - Koyama, Yusei
AU - Röttgering, Huub J.A.
AU - Kodama, Tadayuki
AU - Hayashi, Masao
AU - Hatch, Nina A.
AU - Dannerbauer, Helmut
AU - Tanaka, Ichi
AU - Tadaki, Ken Ichi
AU - Suzuki, Tomoko L.
AU - Fukagawa, Nao
AU - Cai, Zheng
AU - Kurk, Jaron D.
N1 - Funding Information:
Science (JSPS) through JSPS overseas research fellowships. T.K. acknowledges KAKENHI No. 21340045. HD acknowledges financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) under the 2014 Ramón y Cajal program MINECO RYC-2014-15686. We wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.
Funding Information:
RS thanks Emma Rigby for proofreading the manuscript.We thank the anonymous referee for useful comments. The data are collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan, and also based on observations made with the NASA/ESA Hubble Space Telescope, and obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESA) and the Canadian Astronomy Data Centre (CADC/NRC/CSA). We would like to thank the Subaru staff for their support throughout all observing and analysing processes. A part of analyses is conducted with the assistance of the Tool for OPerations on Catalogues And Tables (TOPCAT; Taylor 2015). This work gains the benefit from the 3DHST Treasury Program (GO 12177 and 12328) with NASA/ESA HST, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. This research has made use of data obtained from the Chandra Source Catalogue, provided by the Chandra X-ray Centre (CXC) as part of the Chandra Data Archive, and also use of the NASA/ IPAC Infrared Science Archive, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. R.S. acknowledges the support from the Japan Society for the Promotion of Science (JSPS) through JSPS overseas research fellowships. T.K. acknowledges KAKENHI No. 21340045. HD acknowledges financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) under the 2014 Ramón y Cajal program MINECO RYC-2014-15686. We wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain
Funding Information:
RS thanks Emma Rigby for proofreading the manuscript. We thank the anonymous referee for useful comments. The data are collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan, and also based on observations made with the NASA/ESA Hubble Space Telescope, and obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESA) and the Canadian Astronomy Data Centre (CADC/NRC/CSA). We would like to thank the Subaru staff for their support throughout all observing and analysing processes. A part of analyses is conducted with the assistance of the Tool for OPerations on Catalogues And Tables (TOPCAT; Taylor 2015). This work gains the benefit from the 3D-HST Treasury Program (GO 12177 and 12328) with NASA/ESA HST, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. This research has made use of data obtained from the Chandra Source Catalogue, provided by the Chandra X-ray Centre (CXC) as part of the Chandra Data Archive, and also use of the NASA/ IPAC Infrared Science Archive, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. R.S. acknowledges the support from the Japan Society for the Promotion of
Publisher Copyright:
© 2018 The Author(s).
PY - 2018/12/1
Y1 - 2018/12/1
N2 - This paper is the second in a series presenting the results of our deep Hα-line survey towards protoclusters at z > 2, based on narrow-band imaging with the Subaru Telescope. This work investigates massive galaxies in a protocluster region associated with a radio galaxy (PKS 1138 - 262), the Spiderweb galaxy, at z = 2.2. Our 0.5 mag deeper narrow-band imaging than previous surveys collects a total of 68 Hα emitters (HAE). Here, 17 out of the 68 are newly discovered protocluster members. First, a very high characteristic stellar mass of M⋆* = 1011.73 M⊙ is measured from a Schechter function fit to the mass distribution of HAEs. Together with the Chandra X-ray data, we find that four out of six massive HAEs (M⋆ > 1011 M⊙) show bright X-ray emission, suggesting that they host active galactic nuclei (AGNs). Their mass estimates, therefore, would be affected by the nuclear emission from AGNs. Notably, the X-ray-detected HAEs are likely positioned near the boundary between star-forming and quiescent populations in the rest-frame UVJ plane. Moreover, our deep narrow-band data succeed in probing the bright Hα (+ [N II]) line nebula of the Spiderweb galaxy extending over ~100 physical kpc. These results suggest that the massive galaxies in the Spiderweb protocluster are on the way to becoming the bright red sequence objects seen in local galaxy clusters, where AGNs might play an essential role in their quenching processes, though a more statistical database is needed to build a general picture.
AB - This paper is the second in a series presenting the results of our deep Hα-line survey towards protoclusters at z > 2, based on narrow-band imaging with the Subaru Telescope. This work investigates massive galaxies in a protocluster region associated with a radio galaxy (PKS 1138 - 262), the Spiderweb galaxy, at z = 2.2. Our 0.5 mag deeper narrow-band imaging than previous surveys collects a total of 68 Hα emitters (HAE). Here, 17 out of the 68 are newly discovered protocluster members. First, a very high characteristic stellar mass of M⋆* = 1011.73 M⊙ is measured from a Schechter function fit to the mass distribution of HAEs. Together with the Chandra X-ray data, we find that four out of six massive HAEs (M⋆ > 1011 M⊙) show bright X-ray emission, suggesting that they host active galactic nuclei (AGNs). Their mass estimates, therefore, would be affected by the nuclear emission from AGNs. Notably, the X-ray-detected HAEs are likely positioned near the boundary between star-forming and quiescent populations in the rest-frame UVJ plane. Moreover, our deep narrow-band data succeed in probing the bright Hα (+ [N II]) line nebula of the Spiderweb galaxy extending over ~100 physical kpc. These results suggest that the massive galaxies in the Spiderweb protocluster are on the way to becoming the bright red sequence objects seen in local galaxy clusters, where AGNs might play an essential role in their quenching processes, though a more statistical database is needed to build a general picture.
KW - Galaxies: clusters: individual: PKS 1138-262
KW - Galaxies: evolution
KW - Galaxies: formation
KW - Galaxies: high-redshift
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U2 - 10.1093/MNRAS/STY2618
DO - 10.1093/MNRAS/STY2618
M3 - Article
AN - SCOPUS:85060919691
SN - 0035-8711
VL - 481
SP - 5630
EP - 5650
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -