Evolution of high-redshift (proto)clusters and environmental impact on galaxy quenching

Determine how galaxy clusters and protoclusters at redshifts z ~ 2–4 evolve into low-redshift, more mature clusters, and ascertain the extent to which dense environments affect the formation and quenching of their member galaxies.

Background

The paper investigates the galaxy cluster CLJ1001 at z = 2.51 using JWST/NIRCam, Subaru narrowband imaging, and millimeter CO spectroscopy to achieve a near-complete census of member galaxies, including a population previously missed by HST imaging.

By characterizing a highly concentrated galaxy density profile and a top-heavy stellar mass function among star-forming members, the authors provide evidence that early clusters may assemble from the inside-out and top-to-bottom, offering new insights relevant to the broader unresolved question of how high-redshift (proto)clusters evolve into mature clusters and how environmental density influences member galaxy formation and quenching.

References

However, it is still an open question how these early formed (proto)clusters evolve into low-redshift, more mature clusters and how the dense environments impact the formation and quenching of their member galaxies.

— JWST's first glimpse of a z > 2 forming cluster reveals a top-heavy stellar mass function  (2403.05248 - Sun et al., 2024) in Introduction (Section 1)

The extent to which protocluster core environments affect DSFG evolution at $z>2$ remains unclear, given multiple mechanisms may operate simultaneously.

— The Koi Pond: A Strongly Lensed Protocluster Core hosting a Diverse Population of DSFGs  (2608.15997 - Foo et al., 17 Aug 2026) in Section 4.3, “DSFG Evolution in Protocluster Cores”

However, the statistics related to QGs in protocluster environments is still rather limited and deep dust continuum or CO observations are rare for this type of sources to be able to robustly identify a difference in the residual gas budget of protocluster versus field QGs. Therefore, at the time of writing, our data cannot conclusively establish a stronger gas depletion in QGs induced by their surrounding environment compared to field analogs.

— Rapid quenching and early gas depletion in the core of a galaxy protocluster at z=2.2  (2609.05285 - D'Eugenio et al., 4 Sep 2026) in Section 6.1, “Quenching by gas depletion”