TY - JOUR
T1 - Revealing the Environmental Dependence of Molecular Gas Content in a Distant X-Ray Cluster at z = 2.51
AU - Wang, Tao
AU - Elbaz, David
AU - Daddi, Emanuele
AU - Liu, Daizhong
AU - Kodama, Tadayuki
AU - Tanaka, Ichi
AU - Schreiber, Corentin
AU - Zanella, Anita
AU - Valentino, Francesco
AU - Sargent, Mark
AU - Kohno, Kotaro
AU - Xiao, Mengyuan
AU - Pannella, Maurilio
AU - Ciesla, Laure
AU - Gobat, Raphael
AU - Koyama, Yusei
N1 - Funding Information:
We thank the referee for very constructive comments that helped to improve the quality and clarity of this Letter. We thank Zhi-Yu Zhang for useful discussion on data reduction. This Letter makes use of the data from Karl G. Jansky Very Large Array, operated by the National Radio Astronomy Observatory. This Letter makes use of the following ALMA data: ADS/JAO.ALMA#2016.01155.S and #2011.0.00539. S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), NSC and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. This study was supported by the JSPS Grant-in-Aid for Scientific Research (S) JP17H06130 and the NAOJ ALMA Scientific Research grant No. 2017-06B. T.W. acknowledges support by the the European Commission through the FP7 SPACE project ASTRODEEP (ref. No. 312725). Facilities: VLA, HST, Subaru.
Publisher Copyright:
© 2018. The American Astronomical Society. All rights reserved.
PY - 2018/11/10
Y1 - 2018/11/10
N2 - We present a census of the molecular gas properties of galaxies in the most distant known X-ray cluster, CLJ1001, at z = 2.51, using deep observations of CO(1-0) with the Karl G. Jansky Very Large Array. In total, 14 cluster members with M ∗ > 1010.5 M o are detected, including all of the massive star-forming members within the virial radius, providing the largest galaxy sample in a single cluster at z > 2 with CO(1-0) measurements. We find a large variety in the gas content of these cluster galaxies, which is correlated with their relative positions (or accretion states), with those closer to the cluster core being increasingly gas-poor. Moreover, despite their low gas content, the galaxies in the cluster center exhibit an elevated star formation efficiency (SFE; SFE = SFR/M gas) compared to field galaxies, suggesting that the suppression on the SFR is likely delayed compared to that on the gas content. Their gas depletion time is around t dep ∼ 400 Myr, which is comparable to the cluster dynamical time. This implies that they will consume all of their gas within a single orbit around the cluster center, and form a passive cluster core by z ∼ 2. This result is one of the first direct pieces of evidence for the influence of environment on the gas reservoirs and SFE of z > 2 cluster galaxies, thereby providing new insights into the rapid formation and quenching of the most massive galaxies in the early universe.
AB - We present a census of the molecular gas properties of galaxies in the most distant known X-ray cluster, CLJ1001, at z = 2.51, using deep observations of CO(1-0) with the Karl G. Jansky Very Large Array. In total, 14 cluster members with M ∗ > 1010.5 M o are detected, including all of the massive star-forming members within the virial radius, providing the largest galaxy sample in a single cluster at z > 2 with CO(1-0) measurements. We find a large variety in the gas content of these cluster galaxies, which is correlated with their relative positions (or accretion states), with those closer to the cluster core being increasingly gas-poor. Moreover, despite their low gas content, the galaxies in the cluster center exhibit an elevated star formation efficiency (SFE; SFE = SFR/M gas) compared to field galaxies, suggesting that the suppression on the SFR is likely delayed compared to that on the gas content. Their gas depletion time is around t dep ∼ 400 Myr, which is comparable to the cluster dynamical time. This implies that they will consume all of their gas within a single orbit around the cluster center, and form a passive cluster core by z ∼ 2. This result is one of the first direct pieces of evidence for the influence of environment on the gas reservoirs and SFE of z > 2 cluster galaxies, thereby providing new insights into the rapid formation and quenching of the most massive galaxies in the early universe.
KW - galaxies: ISM
KW - galaxies: clusters: general
KW - galaxies: formation
KW - galaxies: high-redshift
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U2 - 10.3847/2041-8213/aaeb2c
DO - 10.3847/2041-8213/aaeb2c
M3 - Article
AN - SCOPUS:85056729992
SN - 2041-8205
VL - 867
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 2
M1 - L29
ER -