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

Stéphane Blondin·John L. Tonry
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Abstract

We present an algorithm to identify the types of supernova spectra, and determine their redshift and phase. This algorithm, based on the correlation techniques of Tonry & Davis, is implemented in the SuperNova IDentification code (SNID). It is used by members of the ESSENCE project to determine whether a noisy spectrum of a high-redshift supernova is indeed of type Ia, as opposed to, e.g., type Ib/c. Furthermore, by comparing the correlation redshifts obtained using SNID with those determined from narrow lines in the supernova host galaxy spectrum, we show that accurate redshifts (with a typical error < 0.01) can be determined for SNe Ia for which a spectrum of the host galaxy is unavailable. Last, the phase of an input spectrum is determined with a typical accuracy of ~3 days.

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Stéphane Blondin, John L. Tonry. 2006-12-18. Determining the Type, Redshift, and Phase of a Supernova Spectrum. https://doi.org/10.1063/1.2774875

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