SN 2017dio: A Type-Ic Supernova Exploding in a Hydrogen-rich Circumstellar Medium

KUNCARAYAKTI, HANINDYO; MAEDA, KEIICHI; ASHALL, CHRISTOPHER J.; PRENTICE, SIMON J.; MATTILA, SEPPO; KANKARE, ERKKI; FRANSSON, CLAES; LUNDQVIST, PETER; PASTORELLO, ANDREA; LELOUDAS, GIORGOS; ANDERSON, JOSEPH P.; BENETTI, STEFANO; BERSTEN, MELINA C.; CAPPELLARO, ENRICO; CARTIER, RÉGIS; DENNEAU, LARRY; DELLA VALLE, MASSIMO; ELIAS-ROSA, NANCY; FOLATELLI, GASTÓN; FRASER, MORGAN; GALBANY, LLUÍS; GALL, CHRISTA; GAL-YAM, AVISHAY; GUTIÉRREZ, CLAUDIA P.; HAMANOWICZ, ALEKSANDRA; HEINZE, ARI; INSERRA, COSIMO; KANGAS, TUOMAS; MAZZALI, PAOLO; MELANDRI, ANDREA; PIGNATA, GIULIANO; REST, ARMIN; REYNOLDS, THOMAS; ROY, RUPAK; SMARTT, STEPHEN J.; SMITH, KEN W.; SOLLERMAN, JESPER; SOMERO, AUNI; STALDER, BRIAN; STRITZINGER, MAXIMILIAN; TADDIA, FRANCESCO; TOMASELLA, LINA; TONRY, JOHN; WEILAND, HENRY; YOUNG, DAVID R.

The Astrophysical Journal

Astrophysical Journal

Año: 2018 vol. 854

SN 2017dio shows both spectral characteristics of a type-Ic supernova(SN) and signs of a hydrogen-rich circumstellar medium (CSM). Prominent,narrow emission lines of H and He are superposed on the continuum.Subsequent evolution revealed that the SN ejecta are interacting withthe CSM. The initial SN Ic identification was confirmed by removing theCSM interaction component from the spectrum and comparing with known SNeIc and, reversely, adding a CSM interaction component to the spectra ofknown SNe Ic and comparing them to SN 2017dio. Excellent agreement wasobtained with both procedures, reinforcing the SN Ic classification. Thelight curve constrains the pre-interaction SN Ic peak absolute magnitudeto be around {M}g=-17.6 mag. No evidence of significantextinction is found, ruling out a brighter luminosity required by an SNIa classification. These pieces of evidence support the view that SN2017dio is an SN Ic, and therefore the first firm case of an SN Ic withsignatures of hydrogen-rich CSM in the early spectrum. The CSM isunlikely to have been shaped by steady-state stellar winds. The massloss of the progenitor star must have been intense, dot{M}∼0.02{({ε }{{H}α }/0.01)}-1({v}{wind}/500 km s‑1)({v}{shock}/10,000 kms‑1)‑3 M ⊙yr‑1, peaking at a few decades before the SN. Such ahigh mass-loss rate might have been experienced by the progenitorthrough eruptions or binary stripping.Based on observations made with the NOT, operated by the Nordic OpticalTelescope Scientific Association at the Observatorio del Roque de losMuchachos, La Palma, Spain, of the Instituto de Astrofisica de Canarias.This work is based (in part) on observations collected at the EuropeanOrganisation for Astronomical Research in the Southern Hemisphere, Chileas part of PESSTO, (the Public ESO Spectroscopic Survey for TransientObjects Survey) ESO program 188.D-3003, 191.D-0935, 197.D-1075. Based onobservations made with the Liverpool Telescope operated on the island ofLa Palma by Liverpool John Moores University in the Spanish Observatoriodel Roque de los Muchachos of the Instituto de Astrofisica de Canariaswith financial support from the UK Science and Technology FacilitiesCouncil.