The type IIb SN 2008ax: Spectral and light curve evolution

We present spectroscopy and photometry of the He-rich supernova (SN) 2008ax. The early-time spectra show prominent P-Cygni H lines, which decrease with time and disappear completely about 2 months after the explosion. In the same period He i lines become the most prominent spectral features. SN 2008...

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Main Authors: Pastorello, A., Kasliwal, M., Crockett, R., Valenti, S., Arbour, R., Itagaki, K., Kaspi, S., Gal-Yam, A., Smartt, S., Griffith, R., Maguire, K., Ofek, E., Seymour, Nick, Stern, D., Wiethoff, W.
Format: Journal Article
Published: Oxford University Press 2008
Online Access:http://hdl.handle.net/20.500.11937/39180
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author Pastorello, A.
Kasliwal, M.
Crockett, R.
Valenti, S.
Arbour, R.
Itagaki, K.
Kaspi, S.
Gal-Yam, A.
Smartt, S.
Griffith, R.
Maguire, K.
Ofek, E.
Seymour, Nick
Stern, D.
Wiethoff, W.
author_facet Pastorello, A.
Kasliwal, M.
Crockett, R.
Valenti, S.
Arbour, R.
Itagaki, K.
Kaspi, S.
Gal-Yam, A.
Smartt, S.
Griffith, R.
Maguire, K.
Ofek, E.
Seymour, Nick
Stern, D.
Wiethoff, W.
author_sort Pastorello, A.
building Curtin Institutional Repository
collection Online Access
description We present spectroscopy and photometry of the He-rich supernova (SN) 2008ax. The early-time spectra show prominent P-Cygni H lines, which decrease with time and disappear completely about 2 months after the explosion. In the same period He i lines become the most prominent spectral features. SN 2008ax displays the ordinary spectral evolution of a Type IIb supernova. A stringent pre-discovery limit constrains the time of the shock breakout of SN 2008ax to within only a few hours. Its light curve, which peaks in the B band about 20 d after the explosion, strongly resembles that of other He-rich core-collapse supernovae. The observed evolution of SN 2008ax is consistent with the explosion of a young Wolf-Rayet (of WNL type) star, which had retained a thin, low-mass shell of its original H envelope. The overall characteristics of SN 2008ax are reminiscent of those of SN 1993J, except for a likely smaller H mass. This may account for the findings that the progenitor of SN 2008ax was a WNL star and not a K supergiant as in the case of SN 1993J, that a prominent early-time peak is missing in the light curve of SN 2008ax, and that Ha is observed at higher velocities in SN 2008ax than in SN 1993J. © 2008 RAS.
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publishDate 2008
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spelling curtin-20.500.11937-391802017-09-13T14:25:25Z The type IIb SN 2008ax: Spectral and light curve evolution Pastorello, A. Kasliwal, M. Crockett, R. Valenti, S. Arbour, R. Itagaki, K. Kaspi, S. Gal-Yam, A. Smartt, S. Griffith, R. Maguire, K. Ofek, E. Seymour, Nick Stern, D. Wiethoff, W. We present spectroscopy and photometry of the He-rich supernova (SN) 2008ax. The early-time spectra show prominent P-Cygni H lines, which decrease with time and disappear completely about 2 months after the explosion. In the same period He i lines become the most prominent spectral features. SN 2008ax displays the ordinary spectral evolution of a Type IIb supernova. A stringent pre-discovery limit constrains the time of the shock breakout of SN 2008ax to within only a few hours. Its light curve, which peaks in the B band about 20 d after the explosion, strongly resembles that of other He-rich core-collapse supernovae. The observed evolution of SN 2008ax is consistent with the explosion of a young Wolf-Rayet (of WNL type) star, which had retained a thin, low-mass shell of its original H envelope. The overall characteristics of SN 2008ax are reminiscent of those of SN 1993J, except for a likely smaller H mass. This may account for the findings that the progenitor of SN 2008ax was a WNL star and not a K supergiant as in the case of SN 1993J, that a prominent early-time peak is missing in the light curve of SN 2008ax, and that Ha is observed at higher velocities in SN 2008ax than in SN 1993J. © 2008 RAS. 2008 Journal Article http://hdl.handle.net/20.500.11937/39180 10.1111/j.1365-2966.2008.13618.x Oxford University Press unknown
spellingShingle Pastorello, A.
Kasliwal, M.
Crockett, R.
Valenti, S.
Arbour, R.
Itagaki, K.
Kaspi, S.
Gal-Yam, A.
Smartt, S.
Griffith, R.
Maguire, K.
Ofek, E.
Seymour, Nick
Stern, D.
Wiethoff, W.
The type IIb SN 2008ax: Spectral and light curve evolution
title The type IIb SN 2008ax: Spectral and light curve evolution
title_full The type IIb SN 2008ax: Spectral and light curve evolution
title_fullStr The type IIb SN 2008ax: Spectral and light curve evolution
title_full_unstemmed The type IIb SN 2008ax: Spectral and light curve evolution
title_short The type IIb SN 2008ax: Spectral and light curve evolution
title_sort type iib sn 2008ax: spectral and light curve evolution
url http://hdl.handle.net/20.500.11937/39180