2007/08/31 by Stéphane Blondin, S. Blondin, John L. Tonry +1 · 23 citations
Mathematics · Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Correlation #Galaxy #Gamma-ray bursts and supernovae #Mathematics #Neutrino Physics Research #Physics #Redshift #Spectral line #Spectrum (functional analysis) #Supernova #astro-ph
paper · pdf · doi:10.1086/520494
published as Astrophys.J.666:1024-1047,2007 · Appeared in ApJ 666 (2007) 1024. 25 pages, 4 figures. The Supernova Identification (SNID) code can be downloaded from http://www.cfa.harvard.edu/~sblondin/software/snid/index.html
openalex publication_date 2007/08/31 · arxiv created 2007/09/27 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
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 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. Furthermore, by comparing the correlation redshifts obtained using SNID with those determined from narrow lines in the SN host galaxy spectrum, we show that accurate redshifts (with a typical error σ z ≲ 0.01) can be determined for SNe Ia without a spectrum of the host galaxy. Last, the age of an input spectrum is determined with a typical accuracy σ t ≲ 3 days, shown here by using high-redshift SNe Ia with well-sampled light curves. The success of the correlation technique confirms the similarity of some SNe Ia at low and high redshifts. The SNID code, which will be made available to the community, can also be used for comparative studies of SN spectra, as well as comparisons between data and models.