Las Campanas spectroscopic classification of young optical transients
ATel #14253; Regis Cartier (CTIO/NOIRLab), Carlos Contreras(LCO), Alberto Pasten(LCO) and Carla Fuentes (LCO)
on 9 Dec 2020; 06:10 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Carlos Contreras (ccontreras@carnegiescience.edu)
Subjects: Optical, Supernovae
We report the spectroscopic classification of transients discovered by Zwicky Transient Facility (https://www.ztf.caltech.edu/; Kulkarni et al. 2018, ATel #11266) and by the All Sky Automated Survey for SuperNovae ASAS-SN (see Shappee et al. 2014, ApJ, 788, 48 and http://www.astronomy.ohio-state.edu/~assassin/index.shtml ). The ZTF data stream was processed through ALeRCe(https://snhunter.alerce.online/). The observations were performed with the IMACS spectrograph mounted on Walter Baade 6.5-m Magellan telescope on Las Campanas Observatory.
We used SNID (Blondin and Tonry, 2007, ApJ, 666, 1024) cross-correlation software to classify the SN candidates spectra.
We found ZTF20acuxihb and ZTF20acuxrzj spectra match SNe II-P around maximum light.
ZTF20acuwwcx, ZTF20acuxpwz, ZTF20acuzfpk and ASASSN-20pf spectra match young SNe-Ia before maximum light.
ZTF20acuxjus does a good fit a SN-Ic around maximum, while the nature of ZTF20acvmzfv keeps unclear.
Survey name | RA (J2000) | Dec (J(2000)| UT | z | Type | Phase(SNID) | Notes
AT2020abqj | 07:21:16.112 | +22:20:53.73 | Dec07.31 | --- | Var. Star| --- | ---
ASASSN-20pf | 08:21:32.626 | -80:34:01.06 | Dec07.33 | 0.024 | SN Ia | -7 to -4 d | (2,5)
ZTF20acuxihb | 23:59:57.081 | +04:54:06.62 | Dec07.09 | 0.031 | SN II | young | (1)
ZTF20acuwwcx | 22:11:07.095 | -13:57:46.4 | Dec07.07 | 0.088 | SN Ia | -7 to -4 d | (1,5)
ZTF20acuxjus | 00:47:18.922 | +00:24:18.15 | Dec07.12 | 0.058 | SN Ic | near max. | (1,3,5)
ZTF20acuxpwz | 02:40:25.485 | -01:11:48.65 | Dec07.19 | 0.139 | SN Ia | -7 to -4 d | (1,5)
ZTF20acuxrzj | 00:37:44.655 | -05:12:22.42 | Dec07.16 | 0.045 | SN II | young | (1)
ZTF20acuzfpk | 05:13:33.682 | -19:30:05.66 | Dec07.29 | 0.057 | SN Ia | young | (2)
ZTF20acvbvyb | 03:04:50.724 | -01:10:50.10 | Dec07.22 | 0.111 | SN Ia-91T| near max. | (2,5)
ZTF20acvmzfv | 01:00:34.040 | -08:07:00.67 | Dec08.08 | 0.060 | SN? | young | (1,4)
(1) Redshift measured from host galaxy narrow emission lines.
(2) Host galaxy redshift from NED.
(3) Similar to SN 2004aw near maximum light.
(4) The object shows a blue spectrum with very broad spectral features. In particular, a broad spectral feature between 613 and 680 nm could be attributed to Halpha. The object is located in a faint host at z=0.060. At this redshift the absolute magnitude at the discovery was -17.9. A deep non-detection is reported by ZTF two days prior discovery. Follow-up observations are encouraged.
(5) Phase relative to maximum light estimated using SNID.
