Program: GN-2013B-Q-76

The Carnegie Supernova Project~II (CSP~II) is an NSF-funded, 5-year program to obtain optical and near-IR observations of 100-150 Type~Ia supernovae (SNe~Ia) located in the smooth Hubble flow ($0.03 < z < 0.10$). The main emphasis of the CSP~II is to obtain near-IR light curves in order to achieve a distance precision of 1-2\%, as well as to build a definitive low-$z$ reference for NIR observations of SNe~Ia at high-$z$ with HST and next-generation dark energy experiments such as WFIRST. In this proposal, we request time to continue a highly-successful program of near-IR spectroscopic observations of SNe~Ia with GNIRS on Gemini North. These spectra are a key ingredient to achieving the goals of the CSP~II as they will allow the accurate calculation of near-IR K-corrections as a function of light curve phase and shape, which to date are only poorly understood. Moreover, the spectra will provide unique diagnostics of the progenitors and explosion mechanism(s) of SNe~Ia.