DES16C3cje: A low-luminosity, long-lived supernova
Creators: name: Gutiérrez, C. P.
name: Sullivan, M.
name: Martinez, L.
name: Bersten, M. C.
name: Inserra, C.
name: Smith, M.
name: Anderson, J. P.
name: Pan, Y. -C.
name: Pastorello, A.
name: Galbany, L.
name: Nugent, P.
name: Angus, C. R.
name: Barbarino, C.
name: Chen, T. -W.
name: Davis, T. M.
name: Della Valle, M.
name: Foley, R. J.
name: Fraser, M.
name: Frohmaier, C.
name: González-Gaitán, S.
name: Lewis, G. F.
name: Gromadzki, M.
name: Kankare, E.
name: Kokotanekova, R.
name: Kollmeier, J.
name: Magee, M. R.
name: Maguire, K.
name: Möller, A.
name: Morrell, N.
name: Nicholl, M.
name: Pursiainen, M.
name: Sollerman, J.
name: Sommer, N. E.
name: Swann, E.
name: Tucker, B. E.
name: Wiseman, P.
name: Aguena, M.
name: Allam, S.
name: Avila, S.
name: Bertin, E.
name: Brooks, D.
name: Buckley-Geer, E.
name: Burke, D. L.
name: Rosell, A. Carnero
name: Kind, M. Carrasco
name: Carretero, J.
name: Costanzi, M.
name: da Costa, L. N.
name: De Vicente, J.
name: Desai, S.
name: Diehl, H. T.
name: Doel, P.
name: Eifler, T. F.
name: Flaugher, B.
name: Fosalba, P.
name: Frieman, J.
name: García-Bellido, J.
name: Gerdes, D. W.
name: Gruen, D.
name: Gruendl, R. A.
name: Gschwend, J.
name: Gutierrez, G.
name: Hinton, S. R.
name: Hollowood, D. L.
name: Honscheid, K.
name: James, D. J.
name: Kuehn, K.
name: Kuropatkin, N.
name: Lahav, O.
name: Lima, M.
name: Maia, M. A. G.
name: March, M.
name: Menanteau, F.
name: Miquel, R.
name: Morganson, E.
name: Palmese, A.
name: Paz-Chinchón, F.
name: Plazas, A. A.
name: Sako, M.
name: Sanchez, E.
name: Scarpine, V.
name: Schubnell, M.
name: Serrano, S.
name: Sevilla-Noarbe, I.
name: Soares-Santos, M.
name: Suchyta, E.
name: Swanson, M. E. C.
name: Tarle, G.
name: Thomas, D.
name: Varga, T. N.
name: Walker, A. R.
name: Wilkinson, R.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We present DES16C3cje, a low-luminosity, long-lived type II supernova (SN II) at redshift 0.0618, detected by the Dark Energy Survey (DES). DES16C3cje is a unique SN. The spectra are characterized by extremely narrow photospheric lines corresponding to very low expansion velocities of $\lesssim1500$ km s$^{-1}$, and the light curve shows an initial peak that fades after 50 days before slowly rebrightening over a further 100 days to reach an absolute brightness of M$_r\sim -15.5$ mag. The decline rate of the late-time light curve is then slower than that expected from the powering by radioactive decay of $^{56}$Co but is comparable to that expected from accretion power. Comparing the bolometric light curve with hydrodynamical models, we find that DES16C3cje can be explained by either i) a low explosion energy (0.11 foe) and relatively large $^{56}$Ni production of 0.075 M$_{\odot}$ from a $\sim15$ M$_{\odot}$ red supergiant progenitor typical of other SNe II, or ii) a relatively compact $\sim40$ M$_{\odot}$ star, explosion energy of 1 foe, and 0.08 M$_{\odot}$ of $^{56}$Ni. Both scenarios require additional energy input to explain the late-time light curve, which is consistent with fallback accretion at a rate of $\sim0.5\times{10^{-8}}$ M$_{\odot}$ s$^{-1}$.
description: Accepted in MNRAS. 17 pages, 6 figures