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Seven Supernovae classified with the Asiago Telescopes

ATel #5048; P. Ochner, L. Tomasella, A. Pastorello, S. Benetti, E. Cappellaro and M. Turatto (Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica)
on 5 May 2013; 07:26 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 seven supernovae with observations obtained with the 1.82-m Copernico Telescope in Asiago (+ AFOSC; range 340-820 nm, resolution 1.3 nm); and with the Asiago 1.22-m Galileo Telescope (+ B&C; range 400-790 nm; resol. 0.9 nm).

The B&C spectrum obtained on May 04.86 UT of PSN J05415876+6921409 shows that it is a young type-II SN. The spectrum shows a blue continuum with shallow P-Cygni lines of H and and He I. Assuming a recessional velocity of 3934 km/s for the host galaxy NGC 1961 (Strauss et al. 1992, ApJS, 83, 29; Haan et al. 2008, AJ, 135, 232), an expansion velocity of ~10500 km/s is derived from the position of the H-beta minimum. The best match is found with 2006bp around the maximum light (Quimby et al. 2007, ApJ, 666, 1093).

The B&C spectrum obtained on May 04.96 shows that PSN J13265132-1001322 is a peculiar SNIa. Assuming a recessional velocity of 5745 km/s for the host galaxy (Nicolaci da Costa et al. 1998, AJ, 116, 1; this estimate is also consistent with that inferred from the position of a narrow Halpha spectral emission), an expansion velocity of ~10000 km/s is measured from the minimum of the Si II 635nm line. A good match is found with the so-called "super-Chandrasekhar" SNe Ia 2006gz and 2009dc (Hichen et al. 2007, ApJ, 669L, 17; Taubenberger et al. 2011, MNRAS, 412, 2735).

The B&C spectrum obtained on May 05.02 UT shows that PSN J13265132-1001322 is a reddened SNI (most likely a type Ia event). Adopting a recessional velocity of 11716 km/s for the host galaxy (Huchra et al. 2012, ApJS, 199, 26), an expansion velocity of ~11700 km/s is measured from the minimum of the Si-II 635.5 nm line.

The AFOSC spectrum obtained on May 04.82 UT suggests that PSN J11355080+3417027 is a SNII. Together with Balmer lines showing P-Cygni profiles, lines of Fe II, Sc II and the Na I doublet are also detected. Superimposed to the broad supernova features, narrow emission lines of H and [O III] are also detected. From them, we derive a redshift z = 0.021 for the host galaxy, PGC 35860 (in agreement with the redshift of 0.021081 from SDSS Release 5, 2006, via NED).The best fit to the supernova spectral features is obtained with a spectrum of the type IIP SN 1999gi (Leonard et al. 2002, AJ 124, 2490) about one month after the maximum light.

The AFOSC spectrum obtained on May 04.86 UT shows that PSN J11350174+1607168 is a SNIa at redshift z=0.054127 (SDSS Release 6, 2007, via NED). A good match is found with several normal type-Ia supernovae about a week before the maximum light. The expansion velocity, as deduced from the position of the minimum of the Si-II 635.5 nm absorption, is ~13000 km/s.

The AFOSC spectrum obtained on May 04.90 UT shows that PSN J11343649+5453244 is a SNII. The spectrum shows Balmer lines with P-Cygni profiles. From the positions of the H-alpha and H-beta minima, an expansion velocity of ~7500 km/s is derived, assuming a recessional velocity of 5794 km/s for the host galaxy PGC 213858 (from SDSS Data Release 3, 2004, via NED). The best match is found with the type IIP SN 2004et (Sahu et al. 2006, MNRAS 372, 1315; Maguire et al. 2010, MNRAS, 404, 981) about 10-15 days after the explosion.

The AFOSC spectrum obtained on May 05.06 UT shows that PSN J17045368+0907596 is a SNIa at a redshift of about 0.036. A good match is found with several normal SNIa two weeks after the maximum light. The expansion velocity, as deduced from the position of the minimum of the Si-II 635.5 nm absorption, is ~11200 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).