# Environmental Effect on the Interstellar Medium in Galaxies across the Cosmic Web at z=0.73

## TL;DR

This study uses ALMA observations to analyze how different cosmic environments at z~0.7 influence the interstellar medium in galaxies, revealing small dependence on environment but significant effects at intermediate and high densities.

## Contribution

It provides new observational evidence on the environmental impact on galaxy gas content at intermediate redshift using a large ALMA dataset.

## Key findings

- ISM mass shows slight dependence on environment
- Depletion timescale remains constant (~200 Myrs) across environments
- Gas fraction evolution with density parallels cosmic time evolution

## Abstract

We present new ALMA dust continuum observations of 101 $\log(\mathrm{M}_* / \mathrm{M}_\odot)$ > 9.5 galaxies in the COSMOS field to study the effect of environment on the interstellar medium at z ~ 0.7. At this redshift, our targets span a wide range of environments allowing for a diverse sample of galaxies with densities, $\Sigma$ = 0.16-10.5 Mpc$^{-2}$ (per $\Delta$ z = 0.024). Using the ALMA observations, we calculate the total ISM mass and look for depletion as a function of galaxy density in order to understand the quenching or triggering of star formation in galaxies in different environments. ISM mass is found to have a small dependence on environment, while the depletion timescale remains constant (~200 Myrs) across all environments. We find elevated ISM mass values at intermediate densities and lower values at high densities compared to low (field) densities. Our observed evolution in gas fraction with density in this single redshift slice is equivalent to the observed evolution with cosmic time over 2-3 Gyr. To explain the change in gas mass fraction seen in galaxies in intermediate and high densities, these results suggest environmental processes such as mergers and ram pressure stripping are likely playing a role in dense filamentary-cluster environments.