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Title: Broad-lined Supernova 2016coi with a Helium Envelope

Abstract

We present the early-phase spectra and the light curves of the broad-lined (BL) supernova (SN) 2016coi from t = 7 to 67 days after the estimated explosion date. This SN was initially reported as a BL Type SN Ic (SN Ic-BL). However, we found that spectra up to t = 12 days exhibited the He i λ 5876, λ 6678, and λ 7065 absorption lines. We show that the smoothed and blueshifted spectra of normal SNe Ib are remarkably similar to the observed spectrum of SN 2016coi. The line velocities of SN 2016coi were similar to those of SNe Ic-BL and significantly faster than those of SNe Ib. Analyses of the line velocity and light curve suggest that the kinetic energy and the total ejecta mass of SN 2016coi are similar to those of SNe Ic-BL. Together with BL SNe 2009bb and 2012ap, for which the detection of He i was also reported, these SNe could be transitional objects between SNe Ic-BL and SNe Ib, and be classified as BL Type “Ib” SNe (SNe “Ib”-BL). Our work demonstrates the diversity of the outermost layer in BL SNe, which should be related to the variety of the evolutionary paths.

Authors:
 [1]; ;  [2];  [3];  [4]; ; ; ;  [5];  [6];  [7];  [8];  [9];  [10]; ; ; ; ;  [11];  [12] more »; « less
  1. Department of Physics, Faculty of Science and Engineering, Konan University, Okamoto, Kobe, Hyogo 658-8501 (Japan)
  2. Department of Physical Science, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 739-8526 (Japan)
  3. National Astronomical Observatory of Japan, National Institutes of Natural Sciences, Osawa, Mitaka, Tokyo 181-8588 (Japan)
  4. Department of Astronomy, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)
  5. Nishi-Harima Astronomical Observatory, Center for Astronomy, University of Hyogo, 407-2 Nishigaichi, Sayo-cho, Sayo, Hyogo 679-5313 (Japan)
  6. Ishigakijima Astronomical Observatory, National Astronomical Observatory of Japan, National Institutes of Natural Sciences, 1024-1 Arakawa, Ishigaki, Okinawa 907-0024 (Japan)
  7. Institute of Astronomy, Graduate School of Science, The University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan)
  8. Department of Cosmosciences, Graduate School of Science, Hokkaido University, Kita 10 Nishi8, Kita-ku, Sapporo 060-0810 (Japan)
  9. Nobeyama Radio Observatory, National Astronomical Observatory of Japan, National Institutes of Natural Sciences, 462-2 Nobeyama, Minamimaki, Minamisaku, Nagano 384-1305 (Japan)
  10. Department of Astrophysics, Nagoya University, Chikusa-ku, Nagoya 464-8602 (Japan)
  11. Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065 (Japan)
  12. Gunma Astronomical Observatory, Takayama, Gunma 377-0702 (Japan)
Publication Date:
OSTI Identifier:
22661345
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 837; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION; DETECTION; EXPLOSIONS; HELIUM; KINETIC ENERGY; MASS; SPECTRA; SUPERNOVAE; TYPE I SUPERNOVAE; VELOCITY; VISIBLE RADIATION

Citation Formats

Yamanaka, Masayuki, Nakaoka, Tatsuya, Kawabata, Miho, Tanaka, Masaomi, Maeda, Keiichi, Honda, Satoshi, Hosoya, Kensuke, Karita, Mayu, Morihana, Kumiko, Hanayama, Hidekazu, Morokuma, Tomoki, Imai, Masataka, Kinugasa, Kenzo, Murata, Katsuhiro L., Nishimori, Takefumi, Gima, Hirotaka, Ito, Ayano, Morikawa, Yuto, Murakami, Kotone, Hashimoto, Osamu, E-mail: yamanaka@center.konan-u.ac.jp, and and others. Broad-lined Supernova 2016coi with a Helium Envelope. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA5F57.
Yamanaka, Masayuki, Nakaoka, Tatsuya, Kawabata, Miho, Tanaka, Masaomi, Maeda, Keiichi, Honda, Satoshi, Hosoya, Kensuke, Karita, Mayu, Morihana, Kumiko, Hanayama, Hidekazu, Morokuma, Tomoki, Imai, Masataka, Kinugasa, Kenzo, Murata, Katsuhiro L., Nishimori, Takefumi, Gima, Hirotaka, Ito, Ayano, Morikawa, Yuto, Murakami, Kotone, Hashimoto, Osamu, E-mail: yamanaka@center.konan-u.ac.jp, & and others. Broad-lined Supernova 2016coi with a Helium Envelope. United States. doi:10.3847/1538-4357/AA5F57.
Yamanaka, Masayuki, Nakaoka, Tatsuya, Kawabata, Miho, Tanaka, Masaomi, Maeda, Keiichi, Honda, Satoshi, Hosoya, Kensuke, Karita, Mayu, Morihana, Kumiko, Hanayama, Hidekazu, Morokuma, Tomoki, Imai, Masataka, Kinugasa, Kenzo, Murata, Katsuhiro L., Nishimori, Takefumi, Gima, Hirotaka, Ito, Ayano, Morikawa, Yuto, Murakami, Kotone, Hashimoto, Osamu, E-mail: yamanaka@center.konan-u.ac.jp, and and others. Wed . "Broad-lined Supernova 2016coi with a Helium Envelope". United States. doi:10.3847/1538-4357/AA5F57.
@article{osti_22661345,
title = {Broad-lined Supernova 2016coi with a Helium Envelope},
author = {Yamanaka, Masayuki and Nakaoka, Tatsuya and Kawabata, Miho and Tanaka, Masaomi and Maeda, Keiichi and Honda, Satoshi and Hosoya, Kensuke and Karita, Mayu and Morihana, Kumiko and Hanayama, Hidekazu and Morokuma, Tomoki and Imai, Masataka and Kinugasa, Kenzo and Murata, Katsuhiro L. and Nishimori, Takefumi and Gima, Hirotaka and Ito, Ayano and Morikawa, Yuto and Murakami, Kotone and Hashimoto, Osamu, E-mail: yamanaka@center.konan-u.ac.jp and and others},
abstractNote = {We present the early-phase spectra and the light curves of the broad-lined (BL) supernova (SN) 2016coi from t = 7 to 67 days after the estimated explosion date. This SN was initially reported as a BL Type SN Ic (SN Ic-BL). However, we found that spectra up to t = 12 days exhibited the He i λ 5876, λ 6678, and λ 7065 absorption lines. We show that the smoothed and blueshifted spectra of normal SNe Ib are remarkably similar to the observed spectrum of SN 2016coi. The line velocities of SN 2016coi were similar to those of SNe Ic-BL and significantly faster than those of SNe Ib. Analyses of the line velocity and light curve suggest that the kinetic energy and the total ejecta mass of SN 2016coi are similar to those of SNe Ic-BL. Together with BL SNe 2009bb and 2012ap, for which the detection of He i was also reported, these SNe could be transitional objects between SNe Ic-BL and SNe Ib, and be classified as BL Type “Ib” SNe (SNe “Ib”-BL). Our work demonstrates the diversity of the outermost layer in BL SNe, which should be related to the variety of the evolutionary paths.},
doi = {10.3847/1538-4357/AA5F57},
journal = {Astrophysical Journal},
number = 1,
volume = 837,
place = {United States},
year = {Wed Mar 01 00:00:00 EST 2017},
month = {Wed Mar 01 00:00:00 EST 2017}
}