Time Dilation in Type Ia Supernova Spectra at High Redshift

Date

2008

Authors

Blondin, Stephanie
Davis, T M
Krisciunas, Kevin
Sollerman, Jesper
Wood-Vasey, W. Michael
Becker, Andrew C
Challis, Peter M
Clocchiatti, Alejandro
Damke, Guillermo
Filippenko, Alexei

Journal Title

Journal ISSN

Volume Title

Publisher

IOP Publishing

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 and 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 redshifi) 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.

Description

Keywords

Keywords: Cosmology: miscellaneous; Supernovae: general

Citation

Source

Astrophysical Journal, The

Type

Journal article

Book Title

Entity type

Access Statement

License Rights

Restricted until

2037-12-31