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