Aarhus University Seal

Carnegie Supernova Project-II: Near-infrared Spectroscopy of Stripped-envelope Core-collapse Supernovae

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaperJournal articleResearchpeer-review

DOI

  • M. Shahbandeh, Florida State University
  • ,
  • E. Y. Hsiao, Florida State University
  • ,
  • C. Ashall, University of Hawaii at Manoa
  • ,
  • J. Teffs, Liverpool John Moores University
  • ,
  • P. Hoeflich, Florida State University
  • ,
  • N. Morrell, Carnegie Institution of Washington
  • ,
  • M. M. Phillips, Carnegie Institution of Washington
  • ,
  • J. P. Anderson, European Southern Observatory
  • ,
  • E. Baron, Homer L. Dodge Department of Physics and Astronomy
  • ,
  • C. R. Burns, Carnegie Institution of Washington
  • ,
  • C. Contreras, Carnegie Institution of Washington
  • ,
  • S. Davis, Department of Physics, University of California at Davis
  • ,
  • T. R. Diamond, Private Astronomer
  • ,
  • G. Folatelli, CONICET-UNLP)
  • ,
  • L. Galbany, CSIC
  • ,
  • C. Gall, University of Copenhagen
  • ,
  • S. Hachinger, Leibniz Supercomputing Centre
  • ,
  • S. Holmbo
  • E. Karamehmetoglu
  • M. M. Kasliwal, California Institute of Technology
  • ,
  • R. P. Kirshner, Harvard University, Gordon and Betty Moore Foundation
  • ,
  • K. Krisciunas, Texas A and M University
  • ,
  • S. Kumar, Florida State University
  • ,
  • J. Lu, Florida State University
  • ,
  • G. H. Marion, University of Texas at Austin
  • ,
  • P. A. Mazzali, Liverpool John Moores University, Max Planck Institute for Astrophysics
  • ,
  • A. L. Piro, Carnegie Institution of Washington
  • ,
  • D. J. Sand, University of Arizona
  • ,
  • M. D. Stritzinger
  • N. B. Suntzeff, Texas A and M University
  • ,
  • F. Taddia
  • ,
  • S. A. Uddin, Texas A and M University

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.

Original languageEnglish
Article number175
JournalAstrophysical Journal
Volume925
Issue2
Number of pages24
ISSN0004-637X
DOIs
Publication statusPublished - Feb 2022

See relations at Aarhus University Citationformats

ID: 262813781