| Speaker: | Hassen Yesuf (Kavli IPMU) |
|---|---|
| Title: | Relating Morphological Asymmetry and Large-scale Environment to Star formation and Gas Accretion in Galaxies (Postdoc Colloquium) |
| Date (JST): | Fri, Nov 19, 2021, 11:30 - 12:00 |
| Place: | Zoom |
| Related File: | 2704.pdf |
| Abstract: | I will give an overview of my recent and current work on star formation in local galaxies. Gas accretion, dark matter halo mass, and large-scale environment are important drivers of galaxy properties. Gas inflows, while challenging to directly observe, are predicted to regulate the star formation rate (SFR) and metal contents of galaxies. I study the multivariate association among several observable galaxy properties to distinguish the main drivers SFR and Z and test our theoretical understanding of galaxy evolution. In my recent work, I find that the amount of star formation in galaxies is related to morphological asymmetry and central mass concentration. Star-forming galaxies with higher asymmetry and stronger bulges have higher SFR at a given M*. The asymmetry reflects both irregular spiral arms and lopsidedness in seemingly isolated galaxies and structural perturbations by galaxy interactions or mergers. Both merger or direct gas accretions can induce asymmetries, drive gas to the center, elevate SFR, and build a central concentration of stars. Different galaxy evolution models predict drastically different SFR variability timescales, and most evoke black hole feedback to explain SFRs of massive galaxies. The existing evidence points to fairly long-term variations in SFR, ~0.2-2 Gyr, for merger perturbations and similarly for perturbations due to diffuse gas accretion. Currently, I am using HSC imaging data to relate asymmetry to gas-phase metallicity and the large-scale galaxy environments, which in turn are related to gas accretion. I will present some of my preliminary results on these topics. |
| Contact: | https://ipmu.zoom.us/webinar/register/WN_VTTp-bOdQY6GHCMDQrFVIg |
| Remarks: | IPMU Postdoc Colloquium Series Registration necessary from here: https://ipmu.zoom.us/webinar/register/WN_VTTp-bOdQY6GHCMDQrFVIg |
