Thursday

We examine the HI-to-stellar mass ratio (HI fraction) for galaxies near filament backbones within the nearby Universe (d define the filamentary structure of the local cosmic web. HI spectral stacking of HI Parkes All Sky Survey (HIPASS) observations yield the HI fraction for filament galaxies and a field control sample. The HI fraction is measured for different stellar masses and 5th nearest neighbour projected densities (Σ5) to disentangle what influences cold gas in galaxies. For galaxies with stellar masses log(M⋆) ≤ 11 M⊙ in projected densities 0 ≤ Σ5 intra-filament medium which can replenish some HI gas. This supports cold mode accretion where filament galaxies with a large gravitational potential can draw gas from the large scale structure.