https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34329 ⋆) ≤ 11 M_⊙ in projected densities 0 ≤ Σ₅ < 3 galaxies Mpc⁻², all Hɪ fractions of galaxies near filaments are statistically indistinguishable from the control sample. Galaxies with stellar masses log(M_⋆) ≥ 11 M_⊙ have a systematically higher Hɪ fraction near filaments than the control sample. The greatest difference is 0.75 dex, which is 5.5θ difference at mean projected densities of 1.45 galaxies Mpc⁻². We suggest that this is evidence for massive galaxies accreting cold gas from the intrafilament medium that can replenish some Hɪ gas. This supports cold mode accretion where filament galaxies with a large gravitational potential can draw gas from the large-scale structure.]]> Wed 04 Sep 2019 09:39:57 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32088 Galaxy Evolution Explorer near-ultraviolet (NUV) galaxy photometry with the Sloan Digital Sky Survey group catalogue of Yang et al. We compared the (NUV − r) colours of grouped and non-grouped galaxies, and find a significant increase in the fraction of red sequence galaxies with blue (NUV − r) colours outside of groups. When comparing galaxies in mass-matched samples of satellite (non-central), and non-grouped galaxies, we found a >4σ difference in the distribution of (NUV − r) colours, and an (NUV − r) blue fraction >3σ higher outside groups. A comparison of satellite and non-grouped samples has found the NUV fraction is a factor of ∼2 lower for satellite galaxies between 10^10.5 and 10^10.7,M _⊙, showing that higher mass galaxies are more likely to have residual star formation when not influenced by a group potential. There was a higher (NUV − r) blue fraction of galaxies with lower Sérsic indices (n < 3) outside of groups, not seen in the satellite sample. We have used stellar population models of Bruzual & Charlot with multiple burst, or exponentially declining star formation histories to find that many of the (NUV − r) blue non-grouped galaxies can be explained by a slow (∼2 Gyr) decay of star formation, compared to the satellite galaxies. We suggest that taken together, the difference in (NUV − r) colours between samples can be explained by a population of secularly evolving, non-grouped galaxies, where star formation declines slowly. This slow channel is less prevalent in group environments where more rapid quenching can occur.]]> Fri 27 Apr 2018 15:08:51 AEST ]]>