We present spectra of twelve Type Ia supernovae obtained in 1999 at the William Herschel Telescope and the Nordic Optical Telescope during a search for Type Ia supernovae (SN Ia) at intermediate redshift. The spectra range from z=0.178 to z=0.493, including five high signal-to-noise ratio SN Ia spectra in the still largely unexplored range 0.15 < z < 0.3. Most of the spectra were obtained before or around restframe B-band maximum light. None of them shows the peculiar spectral features found in low-redshift over- or under-luminous SN Ia. Expansion velocities of characteristic spectral absorption features such as SiII at 6355 angs., SII at 5640 angs. and CaII at 3945 angs. are found consistent with their low-z SN Ia counterparts.
@article{arxiv.astro-ph/0507703,
title = {Spectroscopy of twelve Type Ia supernovae at intermediate redshift},
author = {C. Balland and M. Mouchet and R. Pain and N. A. Walton and R. Amanullah and P. Astier and R. S. Ellis and S. Fabbro and A. Goobar and D. Hardin and I. M. Hook and M. J. Irwin and R. M. McMahon and J. M. Mendez and P. Ruiz-Lapuente and G. Sainton and K. Schahmaneche and V. Stanishev},
journal= {arXiv preprint arXiv:astro-ph/0507703},
year = {2009}
}
Comments
45 pages, 23 figures. Accepted for publication in A&A