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arXiv · astro-ph/0607363

The Rise Time of Type Ia Supernovae from the Supernova Legacy Survey

Abstract

We compare the rise times of nearby and distant Type Ia supernovae (SNe Ia) as a test for evolution using 73 high-redshift spectroscopically-confirmed SNe Ia from the first two years of the five year Supernova Legacy Survey (SNLS) and published observations of nearby SN. Because of the ``rolling'' search nature of the SNLS, our measurement is approximately 6 times more precise than previous studies, allowing for a more sensitive test of evolution between nearby and distant supernovae. Adopting a simple $t^2$ early-time model (as in previous studies), we find that the rest-frame $B$ rise times for a fiducial SN Ia at high and low redshift are consistent, with values $19.10^{+0.18}_{-0.17}({stat}) \pm 0.2 ({syst})$ and $19.58^{+0.22}_{-0.19}$ days, respectively; the statistical significance of this difference is only 1.4 \sg . The errors represent the uncertainty in the mean rather than any variation between individual SN. We also compare subsets of our high-redshift data set based on decline rate, host galaxy star formation rate, and redshift, finding no substantive evidence for any subsample dependence.

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A. Conley, D. A. Howell, A. Howes, M. Sullivan, P. Astier, D. Balam, S. Basa, R. G. Carlberg, D. Fouchez, J. Guy, I. Hook, J. D. Neill, R. Pain, K. Perrett, C. J. Pritchet, N. Regnault, J. Rich, R. Taillet, E. Aubourg, J. Bronder, R. S. Ellis, S. Fabbro, M. Filiol, D. Le Borgne, N. Palanque-Delabrouille, S. Perlmutter, P. Ripoche. 2006-09-20. The Rise Time of Type Ia Supernovae from the Supernova Legacy Survey. https://doi.org/10.1086/507788

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