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Published February 1, 2022 | Version Submitted + Published
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Carnegie Supernova Project-II: Near-infrared Spectroscopy of Stripped-envelope Core-collapse Supernovae

Creators

  • 1. ROR icon Florida State University
  • 2. ROR icon University of Hawaii at Manoa
  • 3. ROR icon Liverpool John Moores University
  • 4. ROR icon Las Campanas Observatory
  • 5. ROR icon European Southern Observatory
  • 6. ROR icon Carnegie Observatories
  • 7. ROR icon University of California, Davis
  • 8. ROR icon National University of La Plata
  • 9. ROR icon Institute of Space Sciences
  • 10. ROR icon University of Copenhagen
  • 11. ROR icon Leibniz Supercomputing Centre
  • 12. ROR icon Aarhus University
  • 13. ROR icon California Institute of Technology
  • 14. ROR icon Harvard-Smithsonian Center for Astrophysics
  • 15. ROR icon Gordon and Betty Moore Foundation
  • 16. ROR icon Texas A&M University
  • 17. ROR icon The University of Texas at Austin
  • 18. ROR icon Max Planck Institute for Astrophysics
  • 19. ROR icon University of Arizona

Abstract

We present 75 near-infrared (NIR; 0.8−2.5 μm) spectra of 34 stripped-envelope core-collapse supernovae (SESNe) obtained by the Carnegie Supernova Project-II (CSP-II), encompassing optical spectroscopic Types IIb, Ib, Ic, and Ic-BL. The spectra range in phase from pre-maximum to 80 days past maximum. This unique data set constitutes the largest NIR spectroscopic sample of SESNe to date. NIR spectroscopy provides observables with additional information that is not available in the optical. Specifically, the NIR contains the strong lines of He i and allows a more detailed look at whether Type Ic supernovae are completely stripped of their outer He layer. The NIR spectra of SESNe have broad similarities, but closer examination through statistical means reveals a strong dichotomy between NIR "He-rich" and "He-poor" SNe. These NIR subgroups correspond almost perfectly to the optical IIb/Ib and Ic/Ic-BL types, respectively. The largest difference between the two groups is observed in the 2 μm region, near the He i λ2.0581 μm line. The division between the two groups is not an arbitrary one along a continuous sequence. Early spectra of He-rich SESNe show much stronger He i λ2.0581 μm absorption compared to the He-poor group, but with a wide range of profile shapes. The same line also provides evidence for trace amounts of He in half of our SNe in the He-poor group.

Additional Information

© 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2021 October 3; revised 2021 November 16; accepted 2021 November 17; published 2022 February 3. This paper includes data gathered with the 6.5 m Magellan Telescopes at Las Campanas Observatory, Chile. We are pleased to acknowledge the following individuals (in alphabetical order) for their assistance in obtaining the NIR spectroscopic data set: Y. Beletsky, T. Dupuy, R. Foley, L. W. Hsiao. We also thank the Las Campanas Observatory technical staff for their continued support over the years. The CSP-II has been supported by NSF grant Nos. AST-1008343, AST-1613426, AST-1613455, and AST-1613472. C.A. is supported by NASA grant No. 80NSSC19K1717 and NSF grant Nos. AST-1920392 and AST-1911074. J.T. is funded by the consolidated STFC grant No. R276106. L.G. acknowledges financial support from the Spanish Ministry of Science, Innovation and Universities (MICIU) under the 2019 Ramón y Cajal program RYC2019-027683 and from the Spanish MICIU project PID2020-115253GA-I00. C.G. is supported by a Young Investor Grant (25501) from the VILLUM FONDEN. Time domain research by D.J.S. is also supported by NSF grant Nos. AST-1821987, 1813466, 1908972, & 2108032, and by the Heising-Simons Foundation under grant #2020-1864. M.D.S. is supported by grants from the VILLUM FONDEN (grant No. 28021) and the Independent Research Fund Denmark (IRFD; 8021-00170B). Software: firehose (Simcoe et al. 2013), SNID (Blondin & Tonry 2007), SNooPy (Burns et al. 2011), xtellcor (Vacca et al. 2003).

Attached Files

Published - Shahbandeh_2022_ApJ_925_175.pdf

Submitted - 2110.12083.pdf

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2110.12083.pdf

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Additional details

Identifiers

Eprint ID
112875
Resolver ID
CaltechAUTHORS:20220113-182233479

Related works

Describes
https://arxiv.org/abs/2110.12083 (URL)

Funding

NSF
AST-1008343
NSF
AST-1613426
NSF
AST-1613455
NSF
AST-1613472
NASA
80NSSC19K1717
NSF
AST-1920392
NSF
AST-1911074
Science and Technology Facilities Council (STFC)
R276106
Ramón y Cajal Programme
RYC2019-027683
Ministerio de Ciencia, Innovación y Universidades (MICIU)
PID2020-115253GA-I00
Villum Foundation
25501
NSF
AST-1821987
NSF
AST-1813466
NSF
AST-1908972
NSF
AST-2108032
Heising-Simons Foundation
2020-1864
Villum Foundation
28021
Independent Research Fund Denmark
8021-00170B

Dates

Created
2022-01-13
Created from EPrint's datestamp field
Updated
2022-02-08
Created from EPrint's last_modified field

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Astronomy Department