Article

Luminous Radio Emission from the Superluminous Supernova 2017ens at 3.3 yr after Explosion

R. MarguttiDepartment of Astronomy, University of California, Berkeley, CA 94720-3411, USA; [email protected]Joe BrightAstrophysics, Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH, UKDavid MatthewsDepartment of Astronomy, University of California, Berkeley, CA 94720-3411, USA; [email protected]D. L. CoppejansDepartment of Physics, University of Warwick, Coventry CV4 7AL, UKK. D. AlexanderE. BergerCenter for Astrophysics, Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138-1516, USAM. F. BietenholzSARAO/Hartebeesthoek Radio Observatory, PO Box 443, Krugersdorp 1740, South AfricaR. ChornockDepartment of Astronomy, University of California, Berkeley, CA 94720-3411, USA; [email protected]Lindsay DeMarchiAstronomer-in-Residence at Department of Physics Boise State University, 1910 University Drive, Boise, ID 83725-1570, USAM. R. DroutDavid A. Dunlap Department of Astronomy and Astrophysics, University of Toronto 50 St. George Street, Toronto, Ontario, M5S 3H4, CanadaTarraneh EftekhariCenter for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208, USAW. V. Jacobson-GalánDepartment of Astronomy, University of California, Berkeley, CA 94720-3411, USA; [email protected]T. LaskarDepartment of Astrophysics/IMAPP, Radboud University, P.O. Box 9010, 6500 GL, Nijmegen, The NetherlandsD. MilisavljevicIntegrative Data Science Initiative, Purdue University, West Lafayette, IN 47907, USAKohta MuraseCenter for Gravitational Physics and Quantum Information, Yukawa Institute for Theoretical Physics, Kyoto, Kyoto 606-8502, JapanM. NichollAstrophysics Research Centre, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, UKConor M. B. OmandThe Oskar Klein Centre, Department of Astronomy, Stockholm University, AlbaNova, SE-106 91 Stockholm, SwedenM. C. StrohCenter for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208, USAG. TerreranDepartment of Physics, University of California, Santa Barbara, CA 93106-9530, USAB. A. VanderLeyNational Science Foundation, 2415 Eisenhower Avenue, Alexandria, VA 22314, USA

2023en

ABI

Abstract

Abstract We present the results from a multiyear radio campaign of the superluminous supernova (SLSN) SN 2017ens, which yielded the earliest radio detection of an SLSN to date at the age of ∼3.3 yr after explosion. SN 2017ens was not detected at radio frequencies in the first ∼300 days but reached L ν ≈ 10 28 erg s −1 cm −2 Hz −1 at ν ∼ 6 GHz, ∼1250 days post explosion. Interpreting the radio observations in the context of synchrotron radiation from the supernova shock interaction with the circumstellar medium (CSM), we infer an effective mass-loss rate <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>̇</mml:mo> </mml:mrow> </mml:mover> <mml:mo>≈</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>4</mml:mn> </mml:mrow> </mml:msup> <mml:mspace width="0.25em"/> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>☉</mml:mo> </mml:mrow> </mml:msub> <mml:mspace width="0.25em"/> <mml:msup> <mml:mrow> <mml:mi>yr</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:math> at r ∼ 10 17 cm from the explosion’s site, for a wind speed of v w = 50–60 km s −1 as measured from optical spectra. These findings are consistent with the spectroscopic metamorphosis of SN 2017ens from hydrogen poor to hydrogen rich ∼190 days after explosion reported by Chen et al. SN 2017ens is thus an addition to the sample of hydrogen-poor massive progenitors that explode shortly after having lost their hydrogen envelope. The inferred circumstellar densities, implying a CSM mass up to ∼0.5 M ☉ , and low velocity of the ejection suggest that binary interactions (in the form of common-envelope evolution and subsequent envelope ejection) play a role in shaping the evolution of the stellar progenitors of SLSNe in the ≲500 yr preceding core collapse.

Identifiers

DOI: 10.3847/2041-8213/acf1fd

Citations and references

Cited by 10 references

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