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SALT: a Spectral Adaptive Light curve Template for Type Ia Supernovae

J. Guy·P. Astier·S. Nobili·N. Regnault·R. Pain
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Abstract

We present a new method to parameterize Type Ia Supernovae (SN Ia) multi-color light curves. The method was developed in order to analyze the large number of SN Ia multi-color light curves measured in current high-redshift projects. The technique is based on empirically modeling SN Ia luminosity variations as a function of phase, wavelength, a shape parameter, and a color parameter. The model is trained with a sample of well measured nearby SN Ia and then tested with an independent set of supernovae by building an optimal luminosity distance estimator combining the supernova rest-frame luminosity, shape parameter and color reconstructed with the model. The distances we measure using B- and V-band data show a dispersion around the Hubble line comparable or lower than obtained with other methods. With this model, we are able to measure distances using U- and B-band data with a dispersion around the Hubble line of 0.16 +- 0.05.

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J. Guy, P. Astier, S. Nobili, N. Regnault, R. Pain. 2005-07-01. SALT: a Spectral Adaptive Light curve Template for Type Ia Supernovae. https://doi.org/10.1051/0004-6361%3A20053025

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