Determining the Type, Redshift, and Age of a Supernova Spectrum

Understand

We present an algorithm to identify the type of an SN spectrum and to determine its redshift and age.

• This algorithm, based on the correlation techniques of Tonry & Davis, is implemented in the Supernova Identification (SNID) code.
• It is used by members of ongoing high-redshift SN searches to distinguish between type Ia and type Ib/c SNe, and to identify "peculiar" SNe Ia.
• We develop a diagnostic to quantify the quality of a correlation between the input and template spectra, which enables a formal evaluation of the associated redshift error.