Science with an ngVLA - The Molecular High-z Universe on Large Scales: Low-surface-brightness CO and the strength of the ngVLA Core

TL;DR

The ngVLA will enable unprecedented imaging of cold molecular gas in distant galaxies and clusters, revealing large-scale reservoirs that current telescopes cannot detect, thus transforming our understanding of early universe galaxy evolution.

Contribution

This paper presents the scientific case for using the ngVLA core to detect low-surface-brightness CO emission in the high-redshift universe, highlighting its potential to uncover hidden molecular gas reservoirs.

Findings

ngVLA core will detect large-scale cold molecular gas in high-z environments

It will reveal reservoirs of molecular gas previously undetectable by existing telescopes

This will improve understanding of the cold baryon cycle in galaxy evolution

Abstract

The Next-Generation Very Large Array (ngVLA) will revolutionize our understanding of the Early Universe by tracing the coldest phase of molecular gas -the raw ingredient for star formation- in the most distant galaxies and galaxy-clusters. The km-scale core of the ngVLA will be densely packed with antennas, making it a prime instrument for imaging low-surface-brightness emission from large-scale molecular gas in the high-z circum- and inter-galactic medium (CGM/IGM). Recent studies indicate that large amounts of cold molecular gas are hiding in the 10s-100 kpc environments of distant galaxies, but that technical limitations on existing telescope arrays have prevented us from efficiently detecting these large molecular reservoirs. This may have led to a severely biased view of the molecular Universe. We present the science case for low-surface-brightness CO observations of the Early Universe, and how the core of the ngVLA will reveal the cold molecular Universe to limits and at scales not currently detectable by radio telescopes. As such, the ngVLA core will be a powerful instrument for studying the cold baryon cycle that drives the early evolution of galaxies and clusters.