SN 2016B a.k.a. ASASSN-16ab: a transitional Type II supernova
Abstract
We present photometry, polarimetry, and spectroscopy of the Type II supernova ASASSN-16ab/SN 2016B in PGC 037392. The photometric and spectroscopic follow-up commenced about 2 weeks after shock breakout and continued until nearly 6 months. The light curve of SN 2016B exhibits intermediate properties between those of Type IIP and IIL. The early decline is steep (1.68 ± 0.10 mag 100 d-1), followed by a shallower plateau phase (0.47 ± 0.24 mag 100 d-1). The optically thick phase lasts for 118 d, similar to Type IIP. The 56Ni mass estimated from the radioactive tail of the bolometric light curve is 0.082 ± 0.019 M⊙. High-velocity component contributing to the absorption trough of H α and H β in the photospheric spectra are identified from the spectral modelling from about 57-97 d after the outburst, suggesting a possible SN ejecta and circumstellar material interaction. Such high-velocity features are common in the spectra of Type IIL supernovae. By modelling the true bolometric light curve of SN 2016B, we estimated a total ejected mass of ∼15 M⊙, kinetic energy of ∼1.4 foe, and an initial radius of ∼400 R⊙.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- June 2019
- DOI:
- 10.1093/mnras/stz949
- arXiv:
- arXiv:1904.01844
- Bibcode:
- 2019MNRAS.486.2850D
- Keywords:
-
- techniques: photometric;
- techniques: polarimetric;
- techniques: spectroscopic;
- supernovae: general;
- supernovae: individual: ASASSN-16ab/SN 2016B;
- galaxies: individual: PGC 037392;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 16 pages, 4 pages Appendix, 20 figures, 8 tables, Accepted for publication in MNRAS, 01-April-2019