Spectroscopic Confirmation of a Massive Protocluster with Two Substructures at z ≃ 3.1
Abstract
We present the results of a Keck and Northern Extended Millimeter Array spectroscopic survey of 507 galaxies, where we confirm the presence of two massive overdensities at z = 3.090‑3.110 and z = 3.133‑3.155 in the neighborhood of the GOODS-N, each with over a dozen spectroscopically confirmed members. We find that both of these have galaxy overdensities of near-infrared-detected galaxies of δgal,obs = 6‑9 within corrected volumes of (6‑7) × 103 cMpc3. We estimate the properties of the z = 0 descendants of these overdensities using a spherical collapse model and find that both should virialize by z ≃ 0.5‑0.8, with total masses of Mtot ≃ (6‑7) × 1014 M⊙. The same spherical collapse calculations, as well as a clustering-of-clusters statistical analysis, suggest a >80% likelihood that the two overdensities will collapse into a single cluster with Mtot = (1.0‑1.5) × 1015 M⊙ by z ~ 0.1‑0.4. The z = 3.14 substructure contains a core of four bright dusty star-forming galaxies with ΣSFR = 2700 ± 700M⊙ yr‑1 in a volume of only 280 cMpc3.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 2025
- DOI:
- arXiv:
- arXiv:2411.07291
- Bibcode:
- 2025ApJ...979..247N
- Keywords:
-
- High-redshift galaxy clusters;
- Galaxy evolution;
- Redshift surveys;
- 2007;
- 594;
- 1378;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 18 pages, 8 figures. Accepted to ApJ