THE CRITERION OF SUPERNOVA EXPLOSION REVISITED: THE MASS ACCRETION HISTORY
THE CRITERION OF SUPERNOVA EXPLOSION REVISITED: THE MASS ACCRETION HISTORY
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DOI：
10.3847/0004-637x/816/1/43
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发表时间：
2014-06
期刊：
影响因子：
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通讯作者：
Y. Suwa;S. Yamada;T. Takiwaki;K. Kotake
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文献类型：
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作者：
Y. Suwa;S. Yamada;T. Takiwaki;K. Kotake
通过对Woosley和Heger在12到100 M⊙的不同祖元模型下进行球面对称（1D）和轴对称（2D）的中微子辐射流体动力学模拟，我们发现所有的一维运行都没有产生爆炸，而一些二维运行成功了。不同祖星的激波演化的差异可以用它们的质量吸积历史的差异来解释，而质量吸积历史的差异又由祖星的密度结构决定。在大多数模型中，质量吸积历史有两个阶段：早期阶段，质量吸积速率高且迅速下降；后期阶段，质量吸积速率低且几乎恒定。它们被所谓的转折点分开，转折点的起源是吸积层的变化。我们认为，冲击复苏最有可能发生在拐点附近，因此它的位置在M˙L ？>平面可以很好地衡量冲击复苏的可能性：如果转折点位于临界曲线之上，并且系统在此停留较长时间，则会获得冲击复苏。此外，我们开发了一个现象学模型来近似评估M˙L ？>平面，通过少量一维模拟标定自由参数后，仅利用祖细胞的初始密度结构较好地再现了拐点的位置。我们建议将现象学模型应用于大量祖细胞，以便在没有模拟的情况下推断哪些更有可能爆炸。
By performing neutrino-radiation hydrodynamic simulations in spherical symmetry (1D) and axial symmetry (2D) with different progenitor models by Woosley & Heger from 12 to 100 M⊙, we find that all 1D runs fail to produce an explosion and several 2D runs succeed. The difference in the shock evolutions for different progenitors can be interpreted by the difference in their mass accretion histories, which are in turn determined by the density structures of progenitors. The mass accretion history has two phases in the majority of the models: the earlier phase, in which the mass accretion rate is high and rapidly decreasing, and the later phase, with a low and almost constant accretion rate. They are separated by the so-called turning point, the origin of which is a change of the accreting layer. We argue that shock revival will most likely occur around the turning point and hence that its location in the M ˙ – L ?> plane will be a good measure for the possibility of shock revival: if the turning point lies above the critical curve and the system stays there for a long time, shock revival will obtain. In addition, we develop a phenomenological model to approximately evaluate the trajectories in the M ˙ – L ?> plane, which, after calibrating free parameters by a small number of 1D simulations, reproduces the location of the turning point reasonably well by using the initial density structure of progenitor alone. We suggest the application of the phenomenological model to a large collection of progenitors in order to infer without simulations which ones are more likely to explode.