The Carnegie Supernova Project-I: Correlation between Type Ia Supernovae and Their Host Galaxies from Optical to Near-infrared Bands*

Abstract

Abstract We present optical and near-infrared (NIR) (ugriYJH) photometry of host galaxies of Type Ia supernovae (SN Ia) observed by the Carnegie Supernova Project-I. We determine host galaxy stellar masses and, for the first time, study their correlation with SN Ia standardized luminosity across optical and NIR (uBgVriYJH) bands. In the individual bands, we find that SNe Ia are more luminous in more massive hosts with luminosity offsets ranging between −0.07 ± 0.03 and −0.15 ± 0.04 mag after light-curve standardization. The slope of the SN Ia Hubble residual-host mass relation is negative across all uBgVriYJH bands with values ranging between −0.029 ± 0.029 and −0.093 ± 0.031 mag dex−1—implying that SNe Ia in more massive galaxies are brighter than expected. The near-constant observed correlations across optical and NIR bands indicate that dust may not play a significant role in the observed luminosity offset–host mass correlation. We measure projected separations between SNe Ia and their host centers, and find that SNe Ia that explode beyond a projected 10 kpc have a 50%– 60% reduction of the dispersion in Hubble residuals across all bands—making them a more uniform subset of SNe Ia. Dust in host galaxies, peculiar velocities of nearby SN Ia, or a combination of both may drive this result as the color excesses of SNe Ia beyond 10 kpc are found to be generally lower than those interior, but there is also a diminishing trend of the dispersion as we exclude nearby events. We do not find that SN Ia average luminosity varies significantly when they are grouped in various host morphological types. Host galaxy data from this work will be useful, in conjunction with future high-redshift samples, in constraining cosmological parameters.