The Baryonic Tully-Fisher Relation for Galaxies with Supernova Distances

The Baryonic Tully-Fisher Relation (BTFR) is an empirical scaling relation between the baryonic mass of a disk galaxy and its rotational velocity. The resulting relation is used to estimate galaxy distances within the local universe. However, using the BTFR requires adopting a template for the relation derived from precise estimates of a galaxy’s gas mass, stellar mass, and rotational velocity for a collection of galaxies. One of the primary sources of scatter within the BTFR arises from uncertainties in the distances used to derive masses. To minimize distance uncertainties, we construct the BTFR for Type Ia and II supernova host galaxies identified from the Democratic Samples of Supernovae (DSS, Stahl et al. 2021), and crossmatched with the Extragalactic Distance Database (Tully et al. 2009), the Arecibo General Catalog, and the NASA/IPAC Extragalactic Database. Since these galaxies host known supernovae, well-constrained redshift-independent distances have been determined for these galaxies. Here, we present the survey design and preliminary results of our HI study of supernova host galaxies. We are pursuing an observing campaign at the Green Bank Observatory. As part of this project we are executing the observing program GBT 22A-430: “The Baryonic Tully-Fisher Relation for Galaxies with Supernova Distances.” This will yield us 132 observing hours to obtain HI spectra for ~220 galaxies without known, accurate, or accessible HI spectra. Once observed, we will reduce and analyze the HI spectra, allowing us to characterize the HI content, velocities, velocity widths, and other defining characteristics. These observations will be combined with the re-analysis of ~125 galaxies with known, accurate, and accessible archival HI spectra to generate a template BTFR. The resulting template will be one of maximized correlation between the baryonic mass and rotational velocity of a collection of galaxies. Ultimately, this correlation can be used for studies that require approximating galaxy distances within the local universe.