The optical properties of three Type II supernovae: 2014cx, 2014cy, and 2015cz. Issue 1 (22nd March 2021)

• Record Type: Journal Article
• Authors: Dastidar, R; Misra, K; Singh, M; Pastorello, A; Sahu, D K; Wang, X; Gangopadhyay, A; Tomasella, L; Zhang, J; Bose, S; Mo, J; Elias-Rosa, N; Tartaglia, L; Yan, S; Kumar, Brijesh; Anupama, G C; Pandey, S B; Rui, L; Zhang, T; Terreran, G; Ochner, P; Huang, F
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 504:Issue 1(2021)
• Page Start: 1009
• Page End: 1028
• Publication Date: 2021-03-22
• Subjects: techniques: photometric -- techniques: spectroscopic -- supernovae: general -- supernovae: individual: SN 2014cx, SN 2014cy, SN 2015cz -- galaxies: individual: NGC 337, NGC 7742, NGC 582; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stab831
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We present the photometric and spectroscopic analysis of three Type II supernovae (SNe): 2014cx, 2014cy, and 2015cz. SN 2014cx is a conventional Type IIP with shallow slope (0.2 mag/50 d) and an atypical short plateau (∼86 d). SNe 2014cy and 2015cz show relatively large decline rates (0.88 and 1.64 mag/50 d, respectively) at early times before settling to the plateau phase, unlike the canonical Type IIP/L SN light curves. All of them are normal luminosity SN II with an absolute magnitude at mid-plateau of M $_{V, 14\mathrm{ cx}}^{50}$ =$-16.6\, \pm \, 0.4\, \rm {mag}$, M $_{V, 14\mathrm{ cy}}^{50}$ =$-16.5\, \pm \, 0.2\, \rm {mag}$, and M $_{V, 15\mathrm{ cz}}^{50}$ =$-17.4\, \pm \, 0.3\, \rm {mag}$ . A relatively broad range of 56 Ni masses is ejected in these explosions (0.027–0.070 M⊙ ). The spectra shows the classical evolution of SNe II, dominated by a blue continuum with broad H lines at early phases and narrower metal lines with P Cygni profiles during the plateau. High-velocity H i features are identified in the plateau spectra of SN 2014cx at 11 600 kms −1, possibly a sign of ejecta-circumstellar interaction. The spectra of SN 2014cy exhibit strong absorption profile of H i similar to normal luminosity events whereas strong metal lines akin to sub-luminous SNe. The analytical modelling of the bolometric light curve of the three events yields similar progenitor radii within errors (478, 507, and 660 R ⊙ for SNe 2014cx, 2014cy, and 2015cz, respectively), a range of ejecta masses (15.0, 22.2, and 20.6 M ⊙ for SNe 2014cx, 2014cy, and 2015cz), and a modest range of explosion energies (3.3–7.2 foe where 1 foe=10 51 erg).