CaltechAUTHORS
Published December 20, 2019 | Version Submitted + Published
Journal Article Open

Evidence for Late-stage Eruptive Mass Loss in the Progenitor to SN2018gep, a Broad-lined Ic Supernova: Pre-explosion Emission and a Rapidly Rising Luminous Transient

Creators

  • 1. ROR icon California Institute of Technology
  • 2. ROR icon Weizmann Institute of Science
  • 3. ROR icon University of California, Berkeley
  • 4. ROR icon Liverpool John Moores University
  • 5. ROR icon Stockholm University
  • 6. ROR icon Texas Tech University
  • 7. ROR icon University of Washington
  • 8. ROR icon Radboud University Nijmegen
  • 9. ROR icon University of Oxford
  • 10. ROR icon Goddard Space Flight Center
  • 11. ROR icon University of Maryland, College Park
  • 12. ROR icon Universities Space Research Association
  • 13. ROR icon Hebrew University of Jerusalem
  • 14. ROR icon University of California, Santa Cruz
  • 15. ROR icon University College London
  • 16. ROR icon Infrared Processing and Analysis Center
  • 17. ROR icon National Central University
  • 18. ROR icon Lawrence Berkeley National Laboratory
  • 19. ROR icon Harvard-Smithsonian Center for Astrophysics
  • 20. ROR icon Tsinghua University

Abstract

We present detailed observations of ZTF18abukavn (SN2018gep), discovered in high-cadence data from the Zwicky Transient Facility as a rapidly rising (1.4 ± 0.1 mag/hr) and luminous (M_(g,peak) = −20 mag) transient. It is spectroscopically classified as a broad-lined stripped-envelope supernova (Ic-BL SN). The high peak luminosity (L_(bol) ≳ 3×10^(44) erg sec^(−1)), the short rise time (t_(rise) = 3 days in g-band), and the blue colors at peak (g−r ∼ −0.4) all resemble the high-redshift Ic-BL iPTF16asu, as well as several other unclassified fast transients. The early discovery of SN2018gep (within an hour of shock breakout) enabled an intensive spectroscopic campaign, including the highest-temperature (T_(eff) ≳ 40,000 K) spectra of a stripped-envelope SN. A retrospective search revealed luminous (M_g ∼ M_r ≈ −14mag) emission in the days to weeks before explosion, the first definitive detection of precursor emission for a Ic-BL. We find a limit on the isotropic gamma-ray energy release E_(γ,iso) < 4.9×10^(48) erg, a limit on X-ray emission L_X < 10^(40) erg sec^(−1), and a limit on radio emission νL_ν ≲ 10^(37) erg sec^(−1). Taken together, we find that the early (< 10 days) data are best explained by shock breakout in a massive shell of dense circumstellar material (0.02 M_⊙) at large radii (3×10^(14)cm) that was ejected in eruptive pre-explosion mass-loss episodes. The late-time (>10 days) light curve requires an additional energy source, which could be the radioactive decay of Ni-56.

Additional Information

© 2019 The American Astronomical Society. Received 2019 April 24; revised 2019 September 17; accepted 2019 October 1; published 2019 December 18. The code used to produce the results described in this paper was written in Python and is available online in an open-source GitHub repository41 and it is archived on Zenodo (doi:10.5281/zenodo.3534067). When the paper has been accepted for publication, the data will be made publicly available via WISeREP, an interactive repository of supernova data (Yaron & Gal-Yam 2012). The authors would like to thank the anonymous referee whose comments improved the flow, precision, and clarity of the paper. It is a pleasure to thank Tony Piro, Dan Kasen, E. Sterl Phinney, Eliot Quataert, Maryam Modjaz, Jim Fuller, Lars Bildsten, Udi Nakar, Paul Duffell, and Luc Dessart for helpful discussions. A.Y.Q.H. is particularly grateful to Tony Piro and the community at Carnegie Observatories for their hospitality on Tuesdays during the period in which this work was performed. Thank you to the staff at the SMA, AMI, the VLA, Swift, and Chandra for rapidly scheduling and executing the observations. Thank you to David Palmer (LANL) for his assistance in searching the pointing data for Swift/BAT. Thank you to Michael J. Koss (Eureka Scientific Int), Andrew Drake (Caltech), Scott Adams (Caltech), Matt Hankins (Caltech), Kevin Burdge (Caltech), and Kirsty Taggart (LJMU) for assisting with optical spectroscopic observations. Thank you to Erik Petigura and David Hogg for their advice on figure aesthetics. Thank you to David Alexander Kann (IAA-CSIC) for pointing out an error in an early version of the paper posted to the arXiv. D.A.G. thanks Stéfan van der Walt and Ari Crellin-Quick for assistance with skyportal, which enabled the search for pre-explosion emission. A.Y.Q.H. is supported by a National Science Foundation Graduate Research Fellowship under grant No. DGE1144469. This work was supported by the GROWTH project funded by the National Science Foundation under PIRE grant No. 1545949. A.G.-Y. is supported by the EU via ERC grant No. 725161, the ISF, the BSF Transformative program, and by a Kimmel award. Y.T. studied as a GROWTH intern at Caltech during the summer and fall of 2017. C.C.N. thanks the funding from MOST grant 104-2923-M-008-004-MY5. R.L. is supported by a Marie Skłodowska-Curie Individual Fellowship within the Horizon 2020 European Union (EU) Framework Programme for Research and Innovation (H2020-MSCA-IF-2017-794467). A.H. acknowledges support by the I-Core Program of the Planning and Budgeting Committee and the Israel Science Foundation, and support by the ISF grant 647/18. This research was supported by a grant from the GIF, the German-Israeli Foundation for Scientific Research and Development. This research was funded in part by the Gordon and Betty Moore Foundation through Grant GBMF5076, and a grant from the Heising-Simons Foundation. A.C. acknowledges support from the NSF CAREER award N. 1455090 and from the NASA/Chandra GI award N. GO8-19055A. Research support to I.A. is provided by the GROWTH project, funded by the National Science Foundation under grant No 1545949. This work is based on observations obtained with the Samuel Oschin Telescope 48 inch and the 60 inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. Major funding has been provided by the U.S. National Science Foundation under grant No. AST-1440341 and by the ZTF partner institutions: the California Institute of Technology, the Oskar Klein Centre, the Weizmann Institute of Science, the University of Maryland, the University of Washington, Deutsches Elektronen-Synchrotron, the University of Wisconsin–Milwaukee, and the TANGO Program of the University System of Taiwan. Partially based on observations made with the Nordic Optical Telescope, operated by the Nordic Optical Telescope Scientific Association at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofisica de Canarias. The Liverpool Telescope is operated by Liverpool John Moores University with financial support from the UK Science and Technology Facilities Council. LT is located on the island of La Palma, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. The scientific results reported in this article are based in part on observations made by the Chandra X-ray Observatory. The data presented here were obtained in part with ALFOSC, which is provided by the Instituto de Astrofisica de Andalucia (IAA) under a joint agreement with the University of Copenhagen and NOTSA. The Submillimeter Array is a joint project between the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics and is funded by the Smithsonian Institution and the Academia Sinica. We acknowledge the support of the staff of the Xinglong 2.16 m telescope. This work is supported by the National Natural Science Foundation of China (NSFC grants 11325313 and 11633002), and the National Program on Key Research and Development Project (grant No. 2016YFA0400803). SED Machine is based upon work supported by the National Science Foundation under grant No. 1106171. This publication has made use of data collected at Lulin Observatory, partly supported by MoST grant 105-2112-M-008-024-MY3. The JEKYLL simulations were performed on resources provided by the Swedish National Infrastructure for Computing (SNIC) at Parallelldatorcentrum (PDC). Facilities: CFHT - Canada-France-Hawaii Telescope, Keck:I (LRIS) - , Hale (DBSP) - , AMI - , Liverpool:2 m (IO:O - , SPRAT) - , DCT - , Swift (UVOT - , XRT) - , Beijing:2.16 m - , EVLA - , SMA - , LO:1 m - , NOT (ALFOSC). - Software: Astropy (Astropy Collaboration et al. 2013, 2018), IPython (Pérez & Granger 2007), matplotlib (Hunter 2007), numpy (Oliphant 2006), scipy (Jones et al. 2001), extinction (Barbary 2016) SkyPortal (Van der Walt et al. 2019).

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Published - Ho_2019_ApJ_887_169.pdf

Submitted - 1904.11009.pdf

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Additional details

Identifiers

Eprint ID
99014
Resolver ID
CaltechAUTHORS:20191002-100608633

Related works

Describes
https://arxiv.org/abs/1904.11009 (URL)

Funding

NSF Graduate Research Fellowship
DGE-1144469
NSF
AST-1545949
European Research Council (ERC)
725161
Binational Science Foundation (USA-Israel)
Kimmel Award
Caltech
Ministry of Science and Technology (Taipei)
104-2923-M-008-004-MY5
Marie Curie Fellowship
794467
I-CORE Program of the Planning and Budgeting Committee
Israel Science Foundation
647/18
German-Israeli Foundation for Research and Development
Gordon and Betty Moore Foundation
GBMF5076
Heising-Simons Foundation
NSF
AST-1455090
NASA
GO8-19055A
NSF
AST-1545949
NSF
AST-1440341
Oskar Klein Centre
Weizmann Institute of Science
University of Maryland
University of Washington
Deutsches Elektronen-Synchrotron
University of Wisconsin-Milwaukee
University System of Taiwan
Science and Technology Facilities Council (STFC)
Smithsonian Institution
Academia Sinica
National Natural Science Foundation of China
11325313
National Natural Science Foundation of China
11633002
National Program on Key Research and Development Project
2016YFA0400803
NSF
AST-1106171
Ministry of Science and Technology (Taipei)
105-2112-M-008-024-MY3
ZTF partner institutions

Dates

Created
2019-10-02
Created from EPrint's datestamp field
Updated
2021-11-16
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Infrared Processing and Analysis Center (IPAC), Zwicky Transient Facility, Astronomy Department, Division of Geological and Planetary Sciences (GPS)