Our recent work demonstrates a correlation between the high-velocity blue edge, vedge, of the ironpeak
Fe/Co/Ni H-band emission feature and the optical light curve shape of normal, transitional and
sub-luminous type Ia Supernovae (SNe Ia). We explain this correlation in terms of SN Ia physics.
vedge corresponds to the sharp transition between the complete and incomplete silicon burning regions
in the ejecta. It measures the point in velocity space where the outer 56Ni mass fraction, XNi, falls to
the order of 0.03-0.10. For a given 56Ni mass, M(56Ni), vedge is sensitive to the speci c kinetic energy
Ekin(M(56Ni)=MWD) of the corresponding region. Combining vedge with light curve parameters (i.e.,
sBV , m15;s in B and V ) allows us to distinguish between explosion scenarios. The correlation between vedge and light-curve shape is consistent with explosion models near the Chandrasekhar limit. However, the available sub-MCh WD explosion model based on SN 1999by exhibits velocities which are too large to explain the observations. Finally, the sub-luminous SN 2015bo exhibits signatures of a dynamical merger of two WDs demonstrating diversity among explosion scenarios at the faint end of the SNe Ia population.
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Enormous explosion energy of Type IIP SN 2017gmr with bipolar 56Ni ejecta
ABSTRACT The unusual Type IIP SN 2017gmr is revisited in order to pinpoint the origin of its anomalous features, including the peculiar light curve after about 100 d. The hydrodynamic modelling suggests the enormous explosion energy of ≈1052 erg. We find that the light curve with the prolonged plateau/tail transition can be reproduced either in the model with a high hydrogen abundance in the inner ejecta and a large amount of radioactive 56Ni, or in the model with an additional central energy source associated with the fallback/magnetar interaction in the propeller regime. The asymmetry of the late H α emission and the reported linear polarization are reproduced by the model of the bipolar 56Ni ejecta. The similar bipolar structure of the oxygen distribution is responsible for the two-horn structure of the [O i] 6360, 6364 Å emission. The bipolar 56Ni structure along with the high explosion energy are indicative of the magneto-rotational explosion. We identify narrow high-velocity absorption features in H α and He i10 830 Å lines with their origin in the fragmented cold dense shell formed due to the outer ejecta deceleration in a confined circumstellar shell.
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- NSF-PAR ID:
- 10291333
- Date Published:
- Journal Name:
- Monthly Notices of the Royal Astronomical Society
- Volume:
- 505
- Issue:
- 1
- ISSN:
- 0035-8711
- Page Range / eLocation ID:
- 116 to 125
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1093/mnras/stab1369
