2010CBET.2364....1P

J. L. Prieto, Carnegie Observatories; N. Morrell and O. Duhalde, Las Campanas Observatory; and L. A. G. Monard, Pretoria, South Africa, report that they obtained optical spectra (range 380-920 nm; resolution 0.7nm) of 2010fz (cf. CBET 2361) and 2010ga (cf. CBET 2363) on July 11 UT with WFCCD mounted on the du Pont 2.5-m telescope at Las Campanas Observatory. The spectrum of 2010fz shows characteristics of a young, reddened, type-Ia supernova at 1-2 weeks before maximum. After correcting for the recession velocity of its host galaxy (NGC 2967) of 1892 km/s (H I Parkes All-Sky Survey Final Catalog; Wong et al. 2006, MNRAS 371, 1855), a blueshift of the Si II (rest 635.5 nm) line is measured to be 13000 km/s. Strong Na I D absorption is detected from the interstellar medium of our Galaxy (EW = 0.10 nm) and the host galaxy (EW = 0.13 nm), indicative of extinction in the line-of-sight.

SN 2010ga is a type-Ia supernova a few days after maximum light. The redshift of the host galaxy (2MASX J00344266+0954382) is measured to be z = 0.057 from the wavelength of H-alpha in emission (observed wavelength 694.1 nm). Cross-correlation with a library of supernova spectra using SNID (Blondin and Tonry 2007, Ap.J. 666, 1024) shows that 2010ga is most similar to SN 1991T at 11 days after maximum light. Other 1991T-like spectral templates give good cross-correlation fits at a similar age. The redshift obtained by SNID from the cross-correlation, z = 0.056, is fully consistent with the host-galaxy redshift.