450 d of Type II SN 2013ej in optical and near-infrared

Fang Yuan*, Anders Jerkstrand, S. Valenti, J. Sollerman, Ivo R. Seitenzahl, A. Pastorello, S. Schulze, T. W. Chen, Michael J. Childress, M. Fraser, C. Fremling, R. Kotak, Ashley J. Ruiter, Brian P. Schmidt, S. J. Smartt, F. Taddia, G. Terreran, Brad E. Tucker, C. Barbarino, S. BenettiN. Elias-Rosa, A. Gal-Yam, D. A. Howell, C. Inserra, E. Kankare, M. Y. Lee, K. L. Li, Kate Maguire, S. Margheim, A. Mehner, Paolo Ochner, M. Sullivan, Lina Tomasella, D. R. Young

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

38 Citations (Scopus)
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Abstract

We present optical and near-infrared photometric and spectroscopic observations of SN 2013ej, in galaxy M74, from 1 to 450 d after the explosion. SN 2013ej is a hydrogen-rich supernova, classified as a Type IIL due to its relatively fast decline following the initial peak. It has a relatively high peak luminosity (absolute magnitude MV = -17.6) but a small 56Ni production of ~0.023 M. Its photospheric evolution is similar to other Type II SNe, with shallow absorption in the Hα profile typical for a Type IIL. During transition to the radioactive decay tail at ~100 d, we find the SN to grow bluer in B - V colour, in contrast to some other Type II supernovae. At late times, the bolometric light curve declined faster than expected from 56Co decay and we observed unusually broad and asymmetric nebular emission lines. Based on comparison of nebular emission lines most sensitive to the progenitor core mass, we find our observations are best matched to synthesized spectral models with a MZAMS = 12-15 M progenitor. The derived mass range is similar to but not higher than the mass estimated for Type IIP progenitors. This is against the idea that Type IIL are from more massive stars. Observations are consistent with the SN having a progenitor with a relatively low-mass envelope.

Original languageEnglish
Pages (from-to)2003-2018
JournalMonthly Notices of the Royal Astronomical Society
Volume461
Issue number2
Early online date15 Jun 2016
DOIs
Publication statusPublished - 11 Sep 2016

Keywords

  • Supernovae: general
  • Supernovae: individual: SN 2013ej

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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