Type Ia supernovae from very long delayed explosion of core–white dwarf merger
Type Ia supernovae from very long delayed explosion of core–white dwarf merger
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DOI：
10.1111/j.1365-2966.2011.19833.x
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发表时间：
2011-06
影响因子：
4.8
通讯作者：
M. Ilkov;N. Soker
中科院分区：
文献类型：
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作者：
M. Ilkov;N. Soker
本文在Ia型超新星的核简并（CD）框架下研究了快速旋转的白色矮星（WD）的自旋下降时间尺度。在CD方案中，WD的质量是由WD伴星与一颗大质量渐近巨星分支星星的热核合并而成，形成于共同包层阶段的终止或行星状星云阶段。在CD方案中，快速旋转的WD在恒星形成幕之后不久形成，从恒星形成到爆炸的延迟基本上由快速旋转的合并残余物的自旋下降时间决定。我们发现，引力辐射是低效的自旋下降WD，而磁偶极子辐射扭矩可以导致延迟时间，需要解释超新星Ia。为了解释Ia超新星的延迟时间分布，合并残留物的分布应该是dN/dlog（Bsin δ）π常数，对于106 <$Bsin δ <$108 G，其中B是磁偶极值，δ是磁偶极轴与自转轴的夹角。
We study the spinning down time-scale of rapidly rotating white dwarfs (WDs) in the frame of the core-degenerate (CD) scenario for type Ia supernovae (SNe Ia). In the CD scenario, the Chandrasekhar or super-Chandrasekhar mass WD is formed at the termination of the common envelope phase or during the planetary nebula phase, from a merger of a WD companion with the hot core of a massive asymptotic giant branch star. In the CD scenario, the rapidly rotating WD is formed shortly after the stellar formation episode, and the delay from stellar formation to explosion is basically determined by the spin-down time of the rapidly rotating merger remnant. We find that gravitational radiation is inefficient in spinning down WDs, while the magnetodipole radiation torque can lead to delay times that are required to explain SNe Ia. To explain the delay-time-distribution of SNe Ia, the merger remnants distribution should be dN/d log (B sin δ) ≈ constant, for 106≲B sin δ≲ 108 G, where B is the dipole magnetic value and δ the angle between the magnetic dipole axis and rotation axis.