Gas and star formation in galaxies: the role of
environment and (almost) dark galaxies
by Steven Janowiecki (ICRAR/UWA)
Abstract. I will talk about recent work
studying gas and star-formation in samples of galaxies. In particular, using
the new xGASS survey, we have found unusually gas-rich and star-forming central
galaxies in small groups, which we interpret as evidence of feeding from the
cosmic web. At the other extreme, the ALFALFA HI survey is finding gas-rich
galaxies with almost invisible stellar populations. These (almost) dark
galaxies are exceptionally inefficient at forming stars and may be related to
the recently re-discovered class of "ultra-diffuse" galaxies.
