Station Forces Kingston

One of the most important questions in galaxy evolution is why galaxies transition from blue and actively star forming to red and quiescent. While quenched high-mass (stellar mass M ≥ 1011 M ) galaxies are prevalent in the field, suggesting that they may be quenched by internal mechanisms like feedback from active galactic nuclei and virial shock heating (e.g. Birnboim & Dekel 2003; Di Matteo, Springel & Hernquist 2005; Wang & Abel 2008; Kereš et al. 2009; Martig et al.

We report on the discovery of two potential polar ring galaxies (PRGs) in the WALLABY Pilot Data Release 1 (PDR1). These untargeted detections, cross-matched to NGC 4632 and NGC 6156, are some of the first galaxies where the H i observations show two distinct components. We used the iDaVIE virtual reality software to separate the anomalous gas from the galactic gas and found that the anomalous gas comprises ∼50 per cent of the total H i content of both systems.

We study the relative fractions of quenched and star-forming satellite galaxies in the Satellites Around Galactic Analogs (SAGA) survey and Exploration of Local VolumE Satellites (ELVES) program, two nearby and complementary samples of Milky Way-like galaxies that take different approaches to identify faint satellite galaxy populations.