SIMBAD references

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 6355Å, SII at 5640Å and CaII at 3945Å are found to be consistent with those of their low-z SN Ia counterparts.