# [CII] 158 micron Emission from the Host Galaxies of Damped Lyman Alpha Systems

## TL;DR

This study uses ALMA to detect [CII] emission and dust from high-redshift galaxy hosts of Damped Lyman Alpha systems, revealing their similarity to massive star-forming galaxies and their extended gas reservoirs.

## Contribution

First detection of [CII] emission from galaxies associated with high-redshift Damped Lyman Alpha systems using ALMA.

## Key findings

- Detected [CII] 158 micron line and dust emission at z~4
- Host galaxies resemble massive star-forming galaxies
- Extended neutral hydrogen gas reservoirs observed

## Abstract

Gas surrounding high redshift galaxies has been studied through observations of absorption line systems toward background quasars for decades. However, it has proven difficult to identify and characterize the galaxies associated with these absorbers due to the intrinsic faintness of the galaxies compared to the quasars at optical wavelengths. Utilizing the Atacama Large Millimeter/Submillimeter Array, we report on detections of [CII] 158 micron line and dust continuum emission from two galaxies associated with two such absorbers at a redshift of z~4. Our results indicate that the hosts of these high-metallicity absorbers have physical properties similar to massive star-forming galaxies and are embedded in enriched neutral hydrogen gas reservoirs that extend well beyond the star-forming interstellar medium of these galaxies.