The Hubble Space Telescope cluster supernova survey. III. Correlated properties of TYPEIa supernovae and their hosts at 0.9 < z < 1.46

Using the sample of TypeIa supernovae (SNeIa) discovered by the Hubble Space Telescope (HST) Cluster Supernova Survey and augmented with HST-observed SNeIa in the Great Observatories Origins Deep Survey (GOODS) fields, we search for correlations between the properties of SNe and their host galaxies at high redshift. We use galaxy color and quantitative morphology to determine the red sequence in 25 clusters and develop a model to distinguish passively evolving early-type galaxies from star-forming galaxies in both clusters and the field. With this approach, we identify 6 SNIa hosts that are early-type cluster members and 11 SNIa hosts that are early-type field galaxies. We confirm for the first time at z > 0.9 that SNeIa hosted by early-type galaxies brighten and fade more quickly than SNeIa hosted by late-type galaxies. We also show that the two samples of hosts produce SNeIa with similar color distributions. The relatively simple spectral energy distributions expected for passive galaxies enable us to measure stellar masses of early-type SNhosts. In combination with stellar mass estimates of late-type GOODSSNhosts from Thomson & Chary, we investigate the correlation of host mass with Hubble residual observed at lower redshifts. Although the sample is small and the uncertainties are large, a hint of this relation is found at z > 0.9. By simultaneously fitting the average cluster galaxy formation history and dust content to the red-sequence scatters, we show that the reddening of early-type cluster SNhosts is likely E(B - V) ≲ 0.06. The similarity of the field and cluster early-type host samples suggests that field early-type galaxies that lie on the red sequence may also be minimally affected by dust. Hence, the early-type-hosted SNeIa studied here occupy a more favorable environment to use as well-characterized high-redshift standard candles than other SNeIa. © 2012. The American Astronomical Society. All rights reserved.