Type Ia supernova (SN Ia)

White dwarf burns...

Type Ia supernova is the thermonuclear runaway of a white dwarf. It is important due to its applications in other fields such as cosmology (standard candle), galactic chemical evolution (synthesis of Fe-peak elements) and astronomy.

The observed diversity of SN Ia suggests that our understanding about this class of object cannot be complete except when we study how the supernova and its associated nucleosynthesis changes in this vast parameter space.

I use different explosion mechanisms to explain the observation data including:

Supernova light curve and remnant spectra
- Young supernova: SN2011fe, SN2012cg, SN2014J
- Supernova remnant: 3C 397, Sagittarius A
Stellar composition
Galactic chemical evolution and galactic cluster
- E.g., Milky Way and Perseus Cluster

I have studied the supernova explosion model using:

Turbulent deflagration model with/without deflagration-detonation transition
Double detonation model

A movie of a Chandrasekhar mass white dwarf explosion with detonation transtion. Colour is the temperature.

A movie of a sub-Chandrasekhar mass white dwarf explosion. Colour is the temperature

A movie of a Chandrasekhar mass white dwarf explosion assuming no detonation. Colour is the temperature

origin of observed supernova remnants

X-ray Spectra from supernova remnants provide precious data on the abundance ratio of iron-peak elements. They provide the first hand constraints on the supernova progenitor and how it explodes. This figure shows the data point of one nearby supernova remnant 3C 397, which has a high Mn/Ni ratio. Our model suggests its origin as a high mass and high metallicity Chandrasekhar mass white dwarf.

Explaining the origin of observed supernovae

Late-time light curve (after ~500 days) of nearby supernova can provide constraints on the abundance ratios on certain radioactive isotopes, such as Ni-56 and Ni-57. This figure shows two data points obtained also from nearby Type Ia supernovae, SN 2014J and SN 2012cg. Our models show that these supernovae have an origin of whie dwards with a low mass and high metallicity.

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