Time Dilation in Type Ia Supernova Spectra at High Redshift
Abstract
We present multiepoch spectra of 13 high-redshift Type Ia supernovae (SNe Ia) drawn from the literature, the ESSENCE and SNLS projects, and our own separate dedicated program on the ESO Very Large Telescope. We use the Supernova Identification (SNID) code of Blondin & Tonry to determine the spectral ages in the supernova rest frame. Comparison with the observed elapsed time yields an apparent aging rate consistent with the 1/(1+z) factor (where z is the redshift) expected in a homogeneous, isotropic, expanding universe. These measurements thus confirm the expansion hypothesis, while unambiguously excluding models that predict no time dilation, such as Zwicky's "tired light" hypothesis. We also test for power-law dependencies of the aging rate on redshift. The best-fit exponent for these models is consistent with the expected 1/(1+z) factor.
Keywords
Cite
@article{arxiv.0804.3595,
title = {Time Dilation in Type Ia Supernova Spectra at High Redshift},
author = {S. Blondin and T. M. Davis and K. Krisciunas and B. P. Schmidt and J. Sollerman and W. M. Wood-Vasey and A. C. Becker and P. Challis and A. Clocchiatti and G. Damke and A. V. Filippenko and R. J. Foley and P. M. Garnavich and S. W. Jha and R. P. Kirshner and B. Leibundgut and W. Li and T. Matheson and G. Miknaitis and G. Narayan and G. Pignata and A. Rest and A. G. Riess and J. M. Silverman and R. C. Smith and J. Spyromilio and M. Stritzinger and C. W. Stubbs and N. B. Suntzeff and J. L. Tonry and B. E. Tucker and A. Zenteno},
journal= {arXiv preprint arXiv:0804.3595},
year = {2008}
}
Comments
14 pages (emulateapj), 10 figures; accepted for publication in ApJ. Version with full-resolution figures available at http://www.cfa.harvard.edu/~sblondin/publications/timedilation/