LOW MACH NUMBER MODELING OF TYPE IA SUPERNOVAE. IV. WHITE DWARF CONVECTION
LOW MACH NUMBER MODELING OF TYPE IA SUPERNOVAE. IV. WHITE DWARF CONVECTION
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IA 型超新星的低马赫数建模。
DOI：
10.1088/0004-637x/704/1/196
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
S. Woosley
中科院分区：
文献类型：
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作者：
M. Zingale;A. Almgren;John B. Bell;A. Nonaka;S. Woosley
我们提出了第一个三维的，全明星的对流模拟在一个白色矮星之前的Ia型超新星，特别是点火前的最后几个小时。对于这些长时间的计算，我们使用我们的低马赫数流体动力学代码，MAESTRO，我们已经进一步发展到治疗球形恒星为中心的三维笛卡尔几何。所需的主要变化是将一维径向基态映射到笛卡尔网格和从笛卡尔网格映射的过程。我们的模型恢复了以前计算中看到的流的偶极子结构，但我们的长时间积分表明，偶极子的方向随时间而变化。此外，我们显示的发展重力波的外部，稳定的部分的星星。最后，我们发展了几个计算的点火点，并讨论了点火半径的范围。
We present the first three-dimensional, full-star simulations of convection in a white dwarf preceding a Type Ia supernova, specifically the last few hours before ignition. For these long-time calculations, we use our low Mach number hydrodynamics code, MAESTRO, which we have further developed to treat spherical stars centered in a three-dimensional Cartesian geometry. The main change required is a procedure to map the one-dimensional radial base state to and from the Cartesian grid. Our models recover the dipole structure of the flow seen in previous calculations, but our long-time integration shows that the orientation of the dipole changes with time. Furthermore, we show the development of gravity waves in the outer, stable portion of the star. Finally, we evolve several calculations to the point of ignition and discuss the range of ignition radii.