Elentári:a massive proto-supercluster at z ∼ 3.3 in the cosmos field

• Published in: Monthly notices of the Royal Astronomical Society. Letters 2023-11, Vol.526 (1), p.L56-L62
• Main Authors: Forrest, Ben, Lemaux, Brian C, Shah, Ekta, Staab, Priti, McConachie, Ian, Cucciati, Olga, Gal, Roy R, Hung, Denise, Lubin, Lori M, Cassarà, Letizia P, Cassata, Paolo, Chang, Wenjun, Cooper, M C, Decarli, Roberto, Gomez, Percy, Gururajan, Gayathri, Hathi, Nimish, Kashino, Daichi, Marchesini, Danilo, Marsan, Z Cemile, McDonald, Michael, Muzzin, Adam, Shen, Lu, Stawinski, Stephanie Urbano, Talia, Margherita, Vergani, Daniela, Wilson, Gillian, Zamorani, Giovanni
• Format: Article
• Language: English
• ISSN: 1745-3925; 1745-3933
• DOI: 10.1093/mnrasl/slad114

Motivated by spectroscopic confirmation of three overdense regions in the COSMOS field at z ∼ 3.35, we analyse the uniquely deep multiwavelength photometry and extensive spectroscopy available in the field to identify any further related structure. We construct a three-dimensional density map using the Voronoi tesselation Monte Carlo method and find additional regions of significant overdensity. Here, we present and examine a set of six overdense structures at 3.20 < z < 3.45 in the COSMOS field, the most well-characterized of which, PCl J0959 + 0235, has 80 spectroscopically confirmed members and an estimated mass of 1.35 × 1015 M⊙, and is modelled to virialize at z ∼ 1.5−2.0. These structures contain 10 overdense peaks with >5σ overdensity separated by up to 70 cMpc, suggestive of a proto-supercluster similar to the Hyperion system at z ∼ 2.45. Upcoming photometric surveys with JWST such as COSMOS-Web, and further spectroscopic follow-up will enable more extensive analysis of the evolutionary effects that such an environment may have on its component galaxies at these early times.