0 Assigned ID: 3577 ----- Attempting Submission 1 (Fri Mar 25 21:25:48 GMT 2022) ----- The tension between the observed abundant gas and inefficient star formation in low-mass dwarf galaxies of stellar mass Mstar<1e9 Msun make them a critical population to study in order to better understand the significance of different processes that regulate star formation. This proposed archival program aims to leverage extensive archival data to establish a deeper understanding of the baryon cycle in dwarf galaxies. A sample of 30 low-mass dwarfs outside of the Local Group (LG) with Mstar=1e6-1e9 Msun have been identified within 100 kpc of the sightlines of 42 UV bright background QSOs, for which high-quality archival HST COS FUV spectra are available. Nineteen of these are isolated field dwarfs and 11 are satellites with known luminous neighbors at <1 Mpc. Five of the 19 isolated dwarfs have 2-3 QSO probes within 100 kpc, enabling spatially resolved studies of their halo gas. Archival multi-color HST images are available for 15 of these galaxies, providing additional constraints on their star formation history based on resolved stellar population studies. The proposed dwarf galaxy sample will more than double the number of dwarf galaxies beyond LG with known halo gas properties and provide a crucial window into the behavior of the circumgalactic medium (CGM) around well-characterized dwarf galaxies across environments and a broad mass range. The primary objectives of the proposed archival study are: (1) characterizing the extent and chemical enrichment in the CGM around low-mass dwarf galaxies and (2) differentiating the significance between supernova feedback and environmental processes such as tidal and ram-pressure stripping that drive quenching in low-mass dwarfs. PI A. Polzin has experience reducing photometric HST data of dwarf galaxies and conducting analyses involving these data. This experience is specific to low-mass dwarf galaxies and studies of star formation/quenching. Co-PI's E. Boettcher and Z. Qu, and Co-I's H.-W. Chen and S. Johnson are experts in spectroscopic studies of the CGM and its role in galaxy evolution. Co-PI's E. Boettcher, Z. Qu, and Co-I's H.-W. Chen and S. Johnson have extensive experience in the analysis of HST-COS absorption-line spectroscopy, authoring many papers that utilize HST UV spectroscopy in the last five years. Co-I's H.-W. Chen and S. Johnson have significant experience in the development of software for the reduction and analysis of UV spectroscopy from HST. These tools include interfaces for the improvement of the COS wavelength calibration and identification and characterization of absorbers. We will use these tools to expedite the reduction and analysis of the large archival data volumes proposed here. Co-PI's E. Boettcher and Z. Qu and Co-I H.-W. Chen S. Johnson are experts in the CGM of low-mass galaxies and has published multiple papers using HST-COS observations of the CGM of dwarf galaxies. Co-I's H.-W. Chen and S. Johnson is also an expert in photoionization analysis of CGM absorbers. Co-I T. K. Chan is a theorist, involved with the FIRE simulations, which will be used as a complement to the observational study conducted with archival HST data. Intergalactic Medium and the Circumgalactic Medium Galaxies 0 Regular false false true false false false SUPPORTED