Science with an ngVLA. Cold gas in High-z Galaxies: The molecular gas budget

TL;DR

This paper discusses how the ngVLA will enable precise measurements of molecular gas in high-redshift galaxies by observing the CO(1-0) line, significantly advancing our understanding of galaxy evolution over cosmic time.

Contribution

It introduces the use of ngVLA for observing CO(1-0) at high redshift, offering a major increase in detection capability and insights into galaxy evolution.

Findings

Order-of-magnitude more CO detections expected

Enhanced understanding of molecular gas evolution

Observation of gaseous reservoirs from early universe to peak star formation

Abstract

The goal of this science case is to accurately pin down the molecular gas content of high redshift galaxies. By targeting the CO ground transition, we circumvent uncertainties related to CO excitation. The ngVLA can observe the CO(1-0) line at virtually any $z>1.5$, thus exposing the evolution of gaseous reservoirs from the earliest epochs down to the peak of the cosmic history of star formation. The order-of-magnitude improvement in the number of CO detections with respect to state-of-the-art observational campaigns will provide a unique insight on the evolution of galaxies through cosmic time.