Daily Image
09-07-2020
Colloquium 9 July 2020 - Katharina Lutz (CDS - Centre de Donnees astronomique de Strasbourg, Observatoire Astronomique de Strasbourg)
| Submitter: | Katharina Lutz |
| Description: | Title: Average and the not so average HI discs in the nearby universe Abstract: A simple picture of star formation in galaxies is the following: the raw material for star formation is the atomic hydrogen, which can condense into molecular clouds under pressure or in high density environments. Giant molecular clouds are the birth place of stars. When comparing the available amount of cold gas to the star formation rate it also becomes clear that galaxies need to accrete gas from their environment to sustain star formation in the long term. In my talk I present results from two surveys of the atomic hydrogen in nearby galaxies. These surveys aim at understanding how galaxies maintain their HI disc and how characteristics of the HI disc affect star formation. The first survey I will be presenting is the HIX galaxy survey, which targets especially HI rich galaxies. I will show how these galaxies rather maintain and support a large HI disc rather than accreting a lot of gas. This appears to be due to a high baryonic specific angular momentum, which stabilises the HI disc against inflow and star formation. To better understand the HI and baryonic specific angular momentum and their impact on star formation and galaxy evolution, we have started the SHREG galaxy survey. SHREG is based on archival data and has thus far measured detailed 3D kinematic models and the HI specific angular momentum of almost 200 galaxies. I will present first results from this effort in my talk. |
| Copyright: | Katharina Lutz |
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