What Builds and Quenches the Most Massive Galaxies in the Early Universe?

TL;DR

This paper emphasizes the need for next-generation wide-field FIR surveys with large apertures to better understand the formation, assembly, and quenching of the most massive galaxies in the early universe.

Contribution

It highlights the importance of advanced FIR observational capabilities to address current gaps in understanding massive galaxy evolution in the early cosmos.

Findings

Current surveys lack the sensitivity to fully census massive galaxies.

Next-generation FIR facilities are essential for detailed baryon assembly studies.

Understanding early quenching requires wide-field, high-sensitivity FIR observations.

Abstract

The first few billion years of cosmic history witnessed the rapid emergence of the most massive galaxies, yet their true space density, baryon assembly pathways, and early quenching mechanisms remain poorly constrained. Current surveys lack the wide-field, rest-frame FIR sensitivity needed to obtain a complete census of massive systems and to trace their cold gas, dust, and diffuse emission on galactic and circumgalactic scales. A next-generation facility with a very large aperture, wide field of view, and high mapping speed is essential to carry out deep, degree-scale rest-frame FIR surveys. Such capabilities are required to determine how common massive galaxies are, how they assemble their baryons, and what physical processes drive their early transformation and quenching.