Spectroscopic classification of four supernovae at Asiago
ATel #4993; L. Tomasella, A. Pastorello, S. Benetti, E. Cappellaro, M. Turatto, P. Ochner (Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica)
on 19 Apr 2013; 08:15 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Stefano Benetti (stefano.benetti@oapd.inaf.it)
Subjects: Optical, Supernovae, Transient
We report the spectroscopic confirmation of four supernovae with observations obtained with the 1.82-m Copernico Telescope in Asiago (+ AFOSC; range 340-820 nm, resolution 1.3 nm).
Optical spectroscopy obtained on Apr. 18.86 UT shows that CSS130415:121905+422454 is a type-Ia supernova. Adopting a redshift of 0.076 from the fit of the main SN spectral features, a good match is given with SN 1991T spectra at about 10 days after B maximum. The expansion velocity as deduced from the position of the Si-II 635.5nm absorption is about 10400 km/s.
A spectrum obtained on Apr. 18.93 UT shows that CSS130415:130408+435408 is a type-Ia supernova about 5 days before maximum light. The redshift of the host galaxy is about 0.06, as measured from narrow Halpha, [O III] and Hbeta interstellar emission lines detected in the spectrum. The expansion velocity as deduced from the position of the Si-II 635.5nm absorption is about 14300 km/s.
Optical spectroscopy obtained on Apr. 19.04 UT shows that PSN J17172203+4104002 is a type-Ia. Adopting for the host galaxy NGC6343 the redshift z = 0.027612 (Marzke et al. 1996, AJ 112, 1803 via NED), the best fit is obtained with several SNe Ia, few days before maximum light. The expansion velocity as deduced from the position of the Si-II 635.5nm absorption is about 11200 km/s.
A spectrogram obtained on Apr. 19.08 UT shows that PSN J14211513+6134159 is a type-Ia. Adopting for the host galaxy PGC 51271 the redshift z = 0.036446 (SDSS Data Release 2, 2004, via NED), the best fit is obtained with several SNe Ia, about one week before maximum light. The expansion velocity as deduced from the position of the Si-II 635.5nm absorption is about 12700 km/s.
The Asiago classification spectra are posted at this website: URL http://graspa.oapd.inaf.it ; classification was made via GELATO (Harutyunyan et al. 2008, A.Ap. 488, 383) and SNID (Blondin and Tonry 2007, Ap.J. 666, 1024).