Emergence of an Ultrared, Ultramassive Galaxy Cluster Core at z = 4
Abstract
Recent simulations and observations of massive galaxy cluster evolution predict that the majority of stellar mass buildup happens within cluster members by z = 2, before cluster virialization. Protoclusters rich with dusty, star-forming galaxies (DSFGs) at z > 3 are the favored candidate progenitors for these massive galaxy clusters at z ∼ 0. We present here the first study analyzing stellar emission along with cold dust and gas continuum emission in a spectroscopically confirmed z = 4.002 protocluster core rich with DSFGs, the Distant Red Core (DRC). We combine new Hubble Space Telescope and Spitzer data with existing Gemini, Herschel, and Atacama Large Millimeter/submillimeter Array observations to derive individual galaxy-level properties and compare them to coeval field and other protocluster galaxies. All of the protocluster members are massive (>1010 M⊙), but not significantly more so than their coeval field counterparts. Within uncertainty, all are nearly indistinguishable from galaxies on the star-forming versus stellar mass main-sequence relationship and the star formation efficiency plane. Assuming no future major influx of fresh gas, we estimate that these gaseous DSFGs will deplete their gas reservoirs in ∼300 Myr, becoming the massive quiescent ellipticals dominating cluster cores by z ∼ 3. Using various methodologies, we derive a total z = 4 halo mass of ∼1014 M⊙ and estimate that the DRC will evolve to become an ultramassive cluster core of mass ≳1015 M⊙ by z = 0.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 2020
- DOI:
- 10.3847/1538-4357/ab9d1f
- arXiv:
- arXiv:2003.13694
- Bibcode:
- 2020ApJ...898..133L
- Keywords:
-
- High-redshift galaxy clusters;
- Infrared galaxies;
- Galaxy evolution;
- Galaxy clusters;
- 2007;
- 790;
- 594;
- 584;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 16 pages, 7 figures, submitted to ApJ with first round of revisions incorporated