Exploring Correlations Between SNe Ia and their Host Galaxies in the Foundation Supernova Survey DR1 using BayeSN

We apply BayeSN, our new hierarchical Bayesian model for the SEDs of Type Ia supernovae (SNe Ia), to the griz light curves of 157 SNe Ia from the Foundation Supernova Survey’s first data release. We train a new griz version of BayeSN, which we use to model the properties of SNe Ia in the z-band, study the properties of dust in their host galaxies, and construct a Hubble diagram of distances determined from the full griz light curves of the Foundation sample. Additionally, by taking advantage of the broader host mass distribution probed by Foundation (compared to previous low-z surveys), we investigate the possibility that SNe Ia in low- and high-mass host galaxies are extinguished by dust with different RV values. By jointly constraining the intrinsic and dust parameters, we explore whether observed differences between SNe Ia in more and less massive hosts can be explained by a difference in dust properties between these sub-populations, or if an offset remains that cannot be explained by such an effect.