RSAA Colloquia / Seminars / Feast-of-Facts: Thursday, 23 April 2015, 11:00-12:00; Duffield Lecture Theatre

Helga Denes

"A wide-field investigation into the HI content of galaxies"

The environment of a galaxy can play a major role in its evolution. Late-type gas-rich galaxies can be transformed into gas-poor early-type galaxies in dense environments. Observations show that spiral galaxies in galaxy cluster tend to have on average less neutral hydrogen (HI) than galaxies of the same type and size in the field. Recently there is accumulating evidence that HI-deficient galaxies are also relatively frequent in galaxy groups and that galaxy transformation can already start in the group environment. In this talk I will investigate how the environment influences the HI content of galaxies, and which mechanisms are responsible for the gas deficiency in galaxy groups?