Off-Center Carbon Ignition in Rapidly Rotating, Accreting Carbon-Oxygen White Dwarfs
Off-Center Carbon Ignition in Rapidly Rotating, Accreting Carbon-Oxygen White Dwarfs
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DOI：
10.1086/423976
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发表时间：
2004-01
期刊：
影响因子：
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通讯作者：
H. Saio;K. Nomoto
中科院分区：
文献类型：
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作者：
H. Saio;K. Nomoto
研究了恒星自转对碳氧白色矮星吸积富CO物质中碳点火的影响。包括旋转离心力的影响，我们已经计算了各种吸积率的碳点火的演化模型。恒星表面的旋转速度被设定为开普勒速度。恒星内部的角速度是通过考虑湍流粘性引起的角动量输运来确定的。我们已经发现，偏离中心的碳点火发生时，即使恒星旋转的影响，包括如果吸积率是足够高的，临界吸积率的偏离中心点火是很难改变的旋转效果。然而，旋转延迟了点火，即，点火层的质量坐标和点火时白色矮星的质量都比相应的非旋转模型的大。这一结果支持了我们先前的结论，即双白矮星合并不会是Ia型超新星（SN Ia）的前身。
We study the effect of stellar rotation on the carbon ignition in a carbon-oxygen white dwarf accreting CO-rich matter. Including the effect of the centrifugal force of rotation, we have calculated evolutionary models up to the carbon ignition for various accretion rates. The rotational velocity at the stellar surface is set to the Keplerian velocity. The angular velocity in the stellar interior is determined by taking into account the transport of angular momentum due to turbulent viscosity. We have found that an off-center carbon ignition occurs even when the effect of stellar rotation is included if the accretion rate is sufficiently high; the critical accretion rate for the off-center ignition is hardly changed by the effect of rotation. Rotation, however, delays the ignition, i.e., the mass coordinate of the ignition layer and the mass of the white dwarf at the ignition are larger than those for the corresponding nonrotating model. The result supports our previous conclusion that a double-white dwarf merger would not be a progenitor of a Type Ia supernova (SN Ia).