Spectroscopic classification of 3 supernovae with Keck
ATel #13876; G. Terreran, W. V. Jacobson-Galan, P. Blanchard, R. Margutti (Northwestern University), G. Dimitriadis, R. J. Foley (UCSC), L. DeMarchi, A. Baldeschi, M. Stroh, W. Fong, A. Miller, K. Alexander, D. Coppejans, K. Paterson (Northwestern University)
on 18 Jul 2020; 04:46 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Giacomo Terreran (giacomo.terreran@northwestern.edu)
Subjects: Optical, Supernovae, Transient
We report the spectroscopic classification of 3 SNe discovered by the Zwicky Transient Facility (Kulkarni 2018; ATel #11266).
The observations were performed with the DEep Imaging Multi-Object Spectrograph (DEIMOS) mounted on the 10-m Keck II telescope (range 400-900 nm; resolution 0.35 nm).
Survey Name | IAU Name | Discovery MJD | Discovery mag | z | Type. | Phase | Notes
ZTF20ablsunu | SN 2020pjj | 59043.24 | 20.32 | 0.030 | pec-Ia | 4 d after exp. | (1)
ZTF20abkacis | SN 2020orf | 59040.24 | 20.27 | 0.060 | Ia | at peak | (2)
ZTF20ablklei | SN 2020ovk | 59043.36 | 20.27 | 0.025 | II | 4 d after exp. | (3)
(1) The redshift is measured from the narrow features from the host. The relatively prominent carbon features resemble that of SNe Iax (SN 2002cx-like). However, the high velocities of the Si II 635.5 nm feature (-11,800 km/s) makes us favor a Super-Chandrasekhar SN Ia classification. The reported phase is based on the last non-detection.
(2) An expansion velocity of about -10,300 km/s is derived from the position of the minimum of the Si II 635.5 nm feature.
(3) The redshift is retrieved from the NED database, assuming the association of SN 2020ovk with the host KUG 2351+260. The spectrum shows a blue continuum with broad and shallow Balmer lines, consistent with SN 2020ovk being a young Type II SN. The phase is based on the last non-detection.
The classification was done with SNID (Blondin and Tonry 2007, ApJ, 666, 1024).