Studying gas flows in the SUNBIRD starburst galaxies and LIRGs

Gas flows are an important aspect of feedback and the regulation of star formation in galaxies. Nearby starburst galaxies and luminous infrared galaxies (LIRGs) provide extreme environments, where feedback and the changes due to it can be studied in great detail. Understanding the gas flows in these galaxies will help us to understand galaxy evolution better. I will present the results from my recently completed PhD thesis. We studied the resolved gas flows in a sample of 12 nearby (0.0073 ≤ z ≤ 0.0374) starburst galaxies and luminous infrared galaxies in the SUperNovae and starBurst in the InfraReD (SUNBIRD) survey with long-slit spectra from the Southern African Large Telescope. We found evidence of ionized and neutral non-circular gas flows (which includes outflows, inflows and extraplanar gas) in all 12 galaxies at varying velocities. No previous measurements of gas flows had been made for five galaxies (ESO 428-G023, ESO 550-IG025, IRAS 18293-3413, NGC 1819 and NGC 3508). The non-circular gas flow velocities of the 12 galaxies range between 35-182 km/s for the ionized gas and 61-403 km/s for the neutral gas and originate from the nucleus for most of the galaxies. Our results also showed that none of the gas flows are strong enough to leave the galaxies and could possibly cool down to form more stars. This suggests that for these starburst galaxies and LIRGs, even though their star-formation rate is enhanced and gas is flowing outwards, star formation is not necessarily quenched by this, and could continue in the future via the galactic fountain model.