A Search for Massive Galaxy Population in a Protocluster of LAEs at \(z = 2.39\) near the Radio Galaxy 53W002

• Published in: arXiv.org 2022-03
• Main Authors: Yonekura, Naoki, Kajisawa, Masaru, Hamaguchi, Erika, Mawatari, Ken, Yamada, Toru
• Format: Article
• Language: English
• Subjects: Density; Emitters; Galactic clusters; Physical properties; Radio galaxies; Red shift; Reflecting telescopes; Star & galaxy formation; Star formation; Stars & galaxies
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2109.02019

We searched for massive galaxy population in the known large-scale high-density structure of Lyman\(~\alpha\) emitters (LAEs) at \(z=2.39\) near the radio galaxy 53W002 by using \(B,~V,~i^\prime,~J,~H,~{\rm{and}}~K_s\)-bands imaging data taken with Suprime-Cam and MOIRCS on the Subaru telescope. We selected 62 protocluster member candidates by their \(JHK_s\)-band colors and Spectral Energy Distribution (SED) fitting analysis (\(JHK_s\)-selected galaxies) in our survey field of \(70.2~{\rm{arcmin}}^{2}\), and compared their physical properties estimated from the SED fitting with a comparison sample in the COSMOS field. We found significant number density excesses for the \(JHK_s\)-selected galaxies in the 53W002 field at \(K_s2,~{\rm{or}}~V-K_s>4\). In particular the number density of the \(JHK_s\)-selected galaxies with \(K_s2\) in the 53W002 field is nine times higher than the comparison sample. Most of those with \(K_s2\) are massive galaxies with \(M_s>10^{11}~M_\odot\), and their sSFRs of \(10^{-11}\)--\(10^{-10}~\rm{yr^{-1}}\) suggest that the star formation has not yet stopped completely. We also found a density excess of quiescent galaxies with \(M_s=5\times10^{10}\)--\(10^{11}~M_\odot~{\rm{and}}~{\rm{sSFR}}10^{11}~M_\odot\) are not located at the density peaks of LAEs, but widely distributed along the similar direction with the structure of LAEs over \(\sim15\)--\(20\) comoving Mpc. On the other hand, the quiescent galaxies with \({\rm{sSFR}}