English

Gas properties as a function of environment in the proto-supercluster Hyperion at z ~ 2.45

Astrophysics of Galaxies 2025-06-25 v1

Abstract

The cosmic star-formation rate density, molecular gas density and the AGN activity of the Universe peak at z~ 2-3, showing the Universe is most active at this epoch. The nature of the galaxies at these redshifts and their properties as a function of their environment are particularly interesting to understand the mechanisms driving their star-formation and quenching. At z~ 2.5, a massive (~ 4.8 X 10^15 Msun) proto-supercluster, Hyperion, was identified Cucciati et al. 2018, consisting of 7 groups/peaks and extending over a comoving volume of 60 X 60 X 150 Mpc^3, providing an excellent laboratory to probe the properties and evolution of galaxies as a function of their environments. We use a large compilation of photometric (optical to radio wavelengths, COSMOS2020, COSMOS-Super-deblended, and, A3COSMOS) and spectroscopic (C3VO, HST-Hyperion, VUDS, zCOSMOS, DEIMOS10K, MAGAZ3NE) data to assign membership and study the relation between the local environment and the molecular gas mass, the star-formation rate (SFR), gas depletion timescales, and quenching mechanisms. We find that the depletion timescales and the molecular gas fractions decrease and SFR increases in denser environments at the ~ 2 sigma level, suggesting accelerated evolution in the densest regions of this proto-supercluster resulting from gas stripping, over-consumption, and/or cessation of cold flows. Dedicated observations at sub-millimeter wavelengths enabling further spectroscopic confirmation and better coverage in the sub-millimetric (sub-mm) wavelengths can provide more conclusive results on the environmental implications on gas reservoirs of galaxies in Hyperion.

Keywords

Cite

@article{arxiv.2504.08894,
  title  = {Gas properties as a function of environment in the proto-supercluster Hyperion at z ~ 2.45},
  author = {G. Gururajan and O. Cucciati and B. C. Lemaux and M. Talia and G. Zamorani and F. Pozzi and R. Decarli and B. Forrest and L. Shen and G. De Lucia and F. Fontanot and S. Bardelli and D. C. Baxter and L. P. Cassarà and E. Golden-Marx and D. Sikorski and E. A. Shah and R. R. Gal and M. Giavalisco and F. Giddings and N. P. Hathi and D. Hung and A. M. Koekemoer and V. Le Brun and L. M. Lubin and L. A. M. Tasca and L. Tresse and D. Vergani and E. Zucca},
  journal= {arXiv preprint arXiv:2504.08894},
  year   = {2025}
}

Comments

Accepted for publication in A&A. 15 pages, 6 figures, 2 tables