The present-day gas content of simulated field dwarf galaxies

ABSTRACT We examine the gas content of field dwarf galaxies in a high-resolution cosmological simulation. In agreement with previous work, we find that inhabiting dark matter haloes mass below critical value, M200 ≲ Mcrit ≈ 5 × 109 M⊙, are quiescent at present day. The these is thus insensitive to feedback from evolving stars. Almost half systems today have masses much smaller than expected for their mass. gas-deficient originate (1) past interactions massive hosts, which loses and via tidal ram-pressure forces; (2) hydrodynamic gaseous filaments sheets cosmic web, ram pressure. refer as ‘flybys’ ‘COSWEBs’. Flybys locate high-density regions, tracing location most contrast, COSWEBs dispersed throughout volume trace web. For sub-critical systems, < Mcrit, fraction COSWEB can be high $35 {{\ \rm per\ cent}}$, higher flybys, make up 100 per cent $M_{200}\lt 3\times 10^8 \ M_{\odot }$. deficit caused by mechanisms may preclude detection large dwarfs future H i surveys. > web stripping, on average, shuts down star formation more $70{{\ cent}}$ affected systems.