Type I supernovae in the infrared and their use as distance indicators

Abstract

New infrared data for 11 Type I supernovae are presented. These results, when combined with other published data for Type I supernovae, show that the light curves fall into two well-defined groups. The first more common type - Type Ia - shows strong, variable, unexplained absorption at 1.2 μm and probably at 3.5 μm, while the second type - Type Ib - shows no such absorption and a slower decline after maximum. The light curves of the Type Ia supernovae appear to have a dispersion in color and absolute magnitude of ±0.2 mag or less, making them potentially valuable for distance determination within the Local Supercluster.