IA/U.Lisboa Seminar - Massive stars formed in atomic hydrogen reservoirs - 20 abril 2018

I will discuss the process of gas inflow on galaxies and subsequent fuelling of star-formation. Using recent ATCA HI observations I will show that galaxies with anomalous local metallicity decrements (gamma-ray burst host galaxies) have substantial atomic gas reservoirs, and are deficient in molecular gas. This suggests that star formation in these galaxies may be fuelled by recent inflow of metal-poor atomic gas. This is controversial, but can happen in low-metallicity gas near the onset of star formation because cooling of gas (necessary for star formation) is faster than the HI-to-H2 conversion.