| 研究課題/領域番号 |
20J23342
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| 研究機関 | 京都大学 |
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研究代表者 |
方 其亮 京都大学, 理学研究科, 特別研究員(DC1)
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| 研究期間 (年度) |
2020-04-24 – 2023-03-31
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| キーワード | Supernvoa / Transient source / Spectrum |
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| 研究実績の概要 |
We present an analysis of the nebular spectra of 103 stripped-envelope (SE) supernovae (SN). The line profile and width of [O I] are employed to infer the ejecta geometry and the expansion velocity of the inner core, which are then compared with the SN subtypes and [O I]/[Ca II] ratio (an indicator of the progenitor CO core mass).
Based on the best-fit results of the [O I] profile, we conclude that the deviation from spherical symmetry is a common feature for all types of SESNe.
A correlation between [O I] width and [O I]/[Ca II] is discerned, indicating that the oxygen-rich material tends to expand faster for objects with a more massive CO core. Such a correlation can be utilized to constrain the relation between the progenitor mass and the kinetic energy of the explosion.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
The main purpose of this project is to reveal the explosion mechanism of core-collapse supernova (CCSN). To understand the explosion mechanism, there are two factors must be clarified, i.e., how much energy is released during the explosion, and how the energy is distributed. The total amount of energy determines the expansion velocity of the ejecta, which affects the width of the emission lines emerged in the nebular spectrum.
We have confirmed that the line width is positive correlated with the mass of the progenitor. More massive star will tend to release more energy during the explosion. Based on the results of hydrodynamic simulations, we derive the quantitative relation between the progenitor mass and energy, which is crucial to understanding the explosion mechanism.
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| 今後の研究の推進方策 |
In the current work, we have derived the relation between the progenitor mass and the released energy. However, knowing how much energy is released is not enough to reveal the explosion mechanism. How the energy is distributed is also important, which will affect the geometry of the ejecta, and further determines the profile of the emission lines emerged in the nebular spectrum.
In the future work, we will focus on the statistical analysis of the line profile of SESN. We have already confirmed the deviation from spherical symmetry is a common feature base on the analysis of oxygen line. We will further extend the analysis to the calcium line, which traces the configuration of the explosion region. The geometry of the ejecta will put further constrain on the explosion mechanism.
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