The Host Galaxies of Sub-Chandrasekhar Mass Type Ia Supernovae

In recent years, there has been ample evidence for the existence of multiple progenitor pathways that can result in Type Ia supernova (SNe Ia), including SNe Ia of sub-Chandrasekhar mass origin best distinguished by their redder colors and higher Si II velocities near peak brightness. These SNe can contaminate the population of normal events used for cosmological analyses, creating unwanted biases in the final analyses. Given that many current and future surveys using SNe Ia as cosmological probes will not have the resources to take a spectrum of all the events, likely only getting host redshifts long after the SNe Ia have faded, we need to turn to methods that could separate these populations based purely on photometry or host properties. Here, we present a study of a sample of well observed, nearby SNe Ia and their hosts to determine if there are significant enough difference between these populations that can be discerned only from the stellar population properties of their hosts. Our results indicate that the global host properties, including star formation, stellar mass, stellar population age, and dust attenuation, of sub-Chandrasekhar mass explosions do not differ significantly from those of normal mass origin. However, we do find evidence using Na I D equivalent widths that the local environments of sub-Chandrasekhar mass explosions are more dust-affected than normal SNe Ia. Future work requires strengthening photometric probes of sub-Chandrasekhar SNe and their local environments to distinguish these events.