Groups and Protocluster Candidates in the CLAUDS and HSC-SSP Joint Deep Surveys

• Published in: The Astrophysical journal Vol. 933; no. 1; pp. 9 - 28
• Main Authors: Li, Qingyang, Yang, Xiaohu, Liu, Chengze, Jing, Yipeng, He, Min, Huang, Jia-Sheng, Dai, Y. Sophia, Sawicki, Marcin, Arnouts, Stephane, Gwyn, Stephen, Moutard, Thibaud, Mo, H. J., Wang, Kai, Katsianis, Antonios, Cui, Weiguang, Han, Jiaxin, Chiu, I-Non, Gu, Yizhou, Xu, Haojie
• Format: Journal Article
• Language: English
• Published: Philadelphia The American Astronomical Society 01.07.2022; IOP Publishing; American Astronomical Society
• Subjects: Astrophysics; Candidates; Dark matter; Dark matter distribution; Environmental information; Galactic evolution; Galaxies; Galaxy clusters; Galaxy dark matter halos; Galaxy evolution; Galaxy groups; Large-scale structure of the universe; Physics; Protoclusters; Red shift; Sky surveys (astronomy); Stars & galaxies
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/ac6e69

Using the extended halo-based group finder developed by Yang et al., which is able to deal with galaxies via spectroscopic and photometric redshifts simultaneously, we construct galaxy group and candidate protocluster catalogs in a wide redshift range (0 < z < 6) from the joint CFHT Large Area U -band Deep Survey and Hyper Suprime-Cam Subaru Strategic Program deep data set. Based on a selection of 5,607,052 galaxies with i -band magnitude m i < 26 and a sky coverage of 34.41 deg 2 , we identify a total of 2,232,134 groups, of which 402,947 groups have at least three member galaxies. We have visually checked and discussed the general properties of these richest groups at redshift z > 2.0. By checking the galaxy number distributions within a 5–7 h −1 Mpc projected separation and a redshift difference Δ z ≤ 0.1 around those richest groups at redshift z > 2, we identify lists of 761, 343, and 43 protocluster candidates in the redshift bins 2 ≤ z < 3, 3 ≤ z < 4, and z ≥ 4, respectively. In general, these catalogs of galaxy groups and protocluster candidates will provide useful environmental information in probing galaxy evolution along cosmic time.