SN 2016dsg: A Thermonuclear Explosion Involving A Thick Helium Shell
Autor: | Dong, Yize, Valenti, Stefano, Polin, Abigail, Boyle, Aoife, Flörs, Andreas, Vogl, Christian, Kerzendorf, Wolfgang, Sand, David, Jha, Saurabh, Wyrzykowski, Lukasz, Bostroem, K., Pearson, Jeniveve, McCully, Curtis, Andrew, Jennifer, Benettii, Stefano, Blondin, Stephane, Galbany, Lluís, Gromadzki, Mariusz, Hosseinzadeh, Griffin, Howell, D. Andrew, Inserra, Cosimo, Jencson, Jacob, Lundquist, M., Lyman, Joseph, Magee, Mark, Maguire, Kate, Meza, Nicolas, Srivastav, Shubham, Taubenberger, Stefan, Terwel, J, Wyatt, Samuel, Young, David |
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Rok vydání: | 2022 |
Předmět: | |
Druh dokumentu: | Working Paper |
DOI: | 10.3847/1538-4357/ac75eb |
Popis: | A thermonuclear explosion triggered by a helium-shell detonation on a carbon-oxygen white dwarf core has been predicted to have strong UV line blanketing at early times due to the iron-group elements produced during helium-shell burning. We present the photometric and spectroscopic observations of SN 2016dsg, a sub-luminous peculiar Type I SN consistent with a thermonuclear explosion involving a thick He shell. With a redshift of 0.04, the $i$-band peak absolute magnitude is derived to be around -17.5. The object is located far away from its host, an early-type galaxy, suggesting it originated from an old stellar population. The spectra collected after the peak are unusually red, show strong UV line blanketing and weak O I $\lambda$7773 absorption lines, and do not evolve significantly over 30 days. An absorption line around 9700-10500 \AA is detected in the near-infrared spectrum and is likely from the unburnt helium in the ejecta. The spectroscopic evolution is consistent with the thermonuclear explosion models for a sub-Chandrasekhar mass white dwarf with a thick helium shell, while the photometric evolution is not well described by existing models. Comment: accepted for publication in ApJ |
Databáze: | arXiv |
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