Host Galaxy Properties and Hubble Residuals of Type Ia Supernovae from the Nearby Supernova Factory

Understand

We examine the relationship between Type Ia Supernova (SN Ia) Hubble residuals and the properties of their host galaxies using a sample of 115 SNe Ia from the Nearby Supernova Factory (SNfactory).

• We use host galaxy stellar masses and specific star-formation rates fitted from photometry for all hosts, as well as gas-phase metallicities for a subset of 69 star-forming (non-AGN) hosts, to show that the SN Ia Hubble residuals correlate with each of these host properties.
• With these data we find new evidence for a correlation between SN Ia intrinsic color and host metallicity.
• When we combine our data with those of other published SN Ia surveys, we find the difference between mean SN Ia brightnesses in low and high mass hosts is 0.077 +- 0.014 mag.