Asiago spectroscopic classification of three supernovae

ATel #6925; P. Ochner, S. Zaggia, A. Pastorello, S. Benetti, E. Cappellaro, N. Elias-Rosa, L. Tartaglia, G. Terreran, L. Tomasella, M. Turatto (INAF - Osservatorio Astronomico di Padova)
on 15 Jan 2015; 07:54 UT
Credential Certification: Lina Tomasella (lina.tomasella@oapd.inaf.it)

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The Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841) reports the spectroscopic observation of ASASSN-15ar in CGCG 439-010 (ATel #6915), MASTER OT J021447.67+481852.6 in PGC 2314759 (ATel #6885) and ASASSN-15az near 2MASX J11083863-1014456 (ATel #6921). Targets were supplied by the Astronomy Section of the Rochester Academy of Sciences (arXiv:1103.5165) and by the Astronomer's Telegram. The observations were performed with the Asiago 1.82m Copernico Telescope (+AFOSC; range 340-820 nm; resolution 1.4 nm), equipped with the CCD Andor IKON L936.

 
 
Name                          | Date (UT)    |  z         |   Type      | Phase     | Notes 
ASASSN-15ar                   |  20150114.73 |  0.029     |  SN Ia      | -5d       | (1) 
MASTER OT J021447.67+481852.6 |  20150114.77 |  0.036     |  SN Ia      | +2weeks   | (2) 
ASASSN-15az                   |  20150115.13 |  0.028     |  SN Ia      | at max    | (3) 

(1) Excellent match with the type-Ia SN 2004eo (Pastorello et al. 2007, MNRAS 377, 1531). The expansion velicty of the ejected material, as inferred from the position of the absorption of the Si II 635.5 nm line is about 11300 km/s. The host galaxy redshift is from Springhob et al. 2005, ApJS 160, 149 (via NED).

(2) Good matches are obtained with normal type-Ia SNe around 2-3 weeks after maximum.

(3) Best match with several type-Ia SNe around B-band maximum light. The expansion velocity of ASASSN-15az, as deduced from the position of the minimum of the Si-II 635.5nm absorption, is around 11800km/s. The host galaxy redshift z=0.0283 is from Jones at al. 2009, The 6dF Galaxy Survey Data Release 3 (via NED).

Classification was done with GELATO (Harutyunyan et al. 2008, A&A, 488, 383) and SNID (Blondin and Tonry 2007, ApJ, 666, 1024). The Asiago classification spectra are posted at the website http://sngroup.oapd.inaf.it.

Padova Asiago SN group