The Galaxies Associated with the Bimodal Metallicity Distribution
Abstract
We present the first results of the bimodal absorption system imaging campaign (BASIC) program in which we identify the host galaxies for half of the Lehner et al. 2013 sample of Lyman limit systems (16 ≤ log NHI ≤ 19 [cm-2]) using VLT/MUSE and Keck/KCWI integral field unit data. This sample of HI absorbers at z < 1 shows a striking bimodality in metallicity with branches centered on ~2% and 40% solar metallicity. This result hints at the possibility that these branches are tracing cold-mode accretion and gas participating in outflows, recycling, and hot-mode accretion. We identify absorber host galaxies through spectroscopy and covering factor estimates and characterize the host masses, SFRs, metallicities, and inclinations among other properties. With the galaxy information we can test our theory about the types of galaxies we expect to house these metal-rich and metal-poor HI absorbers.
- Publication:
-
American Astronomical Society Meeting Abstracts #235
- Pub Date:
- January 2020
- Bibcode:
- 2020AAS...23541401B