Modeling the Double Detonation Supernova Progenitor CD-30◦11223



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Hot subdwarfs (sdBs) are core-helium burning post main-sequence stars that are stripped of their hydrogen envelopes, often by a binary companion. Compact sdB binaries that exit the mass transfer phase with a period less than about 2 hours are likely to go through another mass transfer phase when the sdB overflows its Roche lobe within its helium burning lifetime. This mass transfer can have signifi- cant consequences if the companion is a sufficiently massive carbon-oxygen white dwarf (CO WD). It was predicted that a sub-Chandrasekhar CO WD can explode under certain conditions. In the context of compact sdB-WD binaries, if the sdB begins mass transfer during its helium burning lifetime and deposits enough he- lium on the WD, it can result in a so-called Double Detonation Type Ia Supernova (SN Ia). CD-30◦11223 was the first system to be identified as a double detonation SN Ia progenitor. In this dissertation, I have modeled this system using the MESA stellar evolution code and studied its evolution till the detonation of the WD. The primary focus has been on studying the sdB evolution while also discussing the orbital evolution of the system, mass transfer properties, and the timeline for the explosion of the WD. The binary feature in MESA has been employed to evolve both components simultaneously. The extensive modeling of the sdB and discussions on the current age and even- tual fate of the system that have been covered in this dissertation will serve as a strong foundation for future work on modeling compact sdB binaries.



stars, type Ia supernovae, compact binaries, subdwarfs