تقرير
Initial Flash and Spectral Formation of Type Ia Supernovae with An Envelope: Applications to Over-luminous SNe Ia
| العنوان: | Initial Flash and Spectral Formation of Type Ia Supernovae with An Envelope: Applications to Over-luminous SNe Ia |
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| المؤلفون: | Maeda, Keiichi, Jiang, Ji-an, Doi, Mamoru, Kawabata, Miho, Shigeyama, Toshikazu |
| سنة النشر: | 2023 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics |
| الوصف: | Over-luminous type Ia supernovae (SNe Ia) show peculiar observational features, for which an explosion of a super-massive white dwarf (WD) beyond the classical Chandrasekhar-limiting mass has been suggested, largely based on their high luminosities and slow light-curve evolution. However, their observational features are diverse, with a few extremely peculiar features whose origins have not been clarified; strong and persisting C II lines, late-time accelerated luminosity decline and red spectra, and a sub-day time-scale initial flash clearly identified so far at least for three over-luminous SNe Ia. In the present work, we suggest a scenario that provides a unified solution to these peculiarities, through hydrodynamic and radiation transfer simulations together with analytical considerations; a C+O-rich envelope (~0.01 - 0.1 Msun) attached to an exploding WD. Strong C II lines are created within the shocked envelope. Dust formation is possible in the late phase, providing a sufficient optical depth thereafter. The range of the envelope mass considered here predicts an initial flash with time-scale of ~0.5 - 3 days. The scenario thus can explain some of the key diverse observational properties by a different amount of the envelope, but additional factors are also required; we argue that the envelope is distributed in a disc-like structure, and also the ejecta properties, e.g., the mass of the WD, plays a key role. Within the context of the hypothesized super-Chandrasekhar-mass WD scenario, we speculatively suggest a progenitor WD evolution including a spin-up accretion phase followed by a spin-down mass-ejection phase. Comment: 11 pages, 5 figures, 1 table. Accepted for publication in MNRAS. Typos corrected and references updated |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1093/mnras/stad618 |
| الوصول الحر: | http://arxiv.org/abs/2302.12387Test |
| رقم الانضمام: | edsarx.2302.12387 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1093/mnras/stad618 |
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