Near-Chandrasekhar-mass Type Ia Supernovae from the Double-degenerate Channel
Near-Chandrasekhar-mass Type Ia Supernovae from the Double-degenerate Channel
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DOI：
10.3847/1538-4357/ac3b52
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发表时间：
2021-11
期刊：
影响因子：
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通讯作者：
Sudarshan Neopane;Khanak Bhargava;R. Fisher;Mckenzie G. Ferrari;S. Yoshida;S. Toonen;E. Bravo
中科院分区：
文献类型：
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作者：
Sudarshan Neopane;Khanak Bhargava;R. Fisher;Mckenzie G. Ferrari;S. Yoshida;S. Toonen;E. Bravo
最近的观测证据表明，白色矮星（WD）合并是一个非常有效的机制，质量吸积到WD在星系中。在本文中，我们表明，WD合并自然产生高度磁化，均匀旋转的WD，包括一个很大的人口在一个狭窄的质量范围内接近的Mrachasekhar质量（M Ch）。这些近M Ch WD合并随后经历了快速的旋转和压缩的102年的时间尺度上，要么导致中心点火和正常的SN Ia通过DDT机制，或替代失败的爆炸和SN Iax通过纯爆燃。由此产生的SNe Ia和SNe Iax将具有光谱、光变曲线、偏振测量和核合成产额，与通过典型的近M Ch单简并（SD）通道产生的预测相似，但具有双简并通道的t −1延迟时间分布特征。此外，与SD信道相反，接近M Ch SNe Ia和SNe Iax的WD合并将不产生可观察的伴随签名。我们讨论了一系列的影响，这些发现，从超新星Ia爆炸机制，银河核合成的铁峰元素，包括锰。
Recent observational evidence has demonstrated that white dwarf (WD) mergers are a highly efficient mechanism for mass accretion onto WDs in the galaxy. In this paper, we show that WD mergers naturally produce highly magnetized, uniformly rotating WDs, including a substantial population within a narrow mass range close to the Chandrasekhar mass (M Ch). These near-M Ch WD mergers subsequently undergo rapid spin up and compression on a ∼ 102 yr timescale, either leading to central ignition and a normal SN Ia via the DDT mechanism, or alternatively to a failed detonation and SN Iax through pure deflagration. The resulting SNe Ia and SNe Iax will have spectra, light curves, polarimetry, and nucleosynthetic yields similar to those predicted to arise through the canonical near-M Ch single degenerate (SD) channel, but with a t −1 delay time distribution characteristic of the double-degenerate channel. Furthermore, in contrast to the SD channel, WD merger near-M Ch SNe Ia and SNe Iax will not produce observable companion signatures. We discuss a range of implications of these findings, from SNe Ia explosion mechanisms, to galactic nucleosynthesis of iron peak elements including manganese.