Semi-dynamical approach to the shock revival in core-collapse supernovae
Semi-dynamical approach to the shock revival in core-collapse supernovae
复制标题
核心塌陷超新星激波复兴的半动力学方法
DOI：
10.1088/0004-637x/765/2/123
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Shoichi Yamada
中科院分区：
文献类型：
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作者：
Hiroki Nagakura;Yu Yamamoto;Shoichi Yamada
我们发展了一种新的半动力学方法来研究核心坍缩超新星中中微子加热引起的激波复活。我们的新方法是以前的研究，采用球对称的，稳定的，冲击吸积流与灯泡近似的延伸。后者已被广泛用于超新星社区的现象学研究的标准，成功的超新星爆炸。在本方法中，我们摆脱了稳态条件，并考虑冲击波运动。我们考虑的情况下，它不是临界光度，但临界波动所产生的流体动力学不稳定性，如驻吸积激波不稳定性和中微子驱动的对流，在激波后的区域，决定了冲击波复苏的开始。在确认新方法确实定性地捕获了复苏冲击波的动力学之后，我们然后将该方法应用于各种初始条件，并发现存在冲击复苏的临界波动，可以通过以下公式很好地拟合：f crit <$0.8 ×（M in/1.4 M反馈）×{1−（r sh/10 8 cm）}，其中f crit表示由未扰动的冲击后值标准化的临界压力波动。M in和r sh分别代表中心致密物体的质量和冲击波半径。临界涨落随激波半径的增大而减小，随中心物体质量的增大而增大。我们讨论了我们的结果可能产生的影响，三维冲击复兴，这是目前在超新星社区有争议的。
We develop a new semi-dynamical method to study shock revival by neutrino heating in core-collapse supernovae. Our new approach is an extension of the previous studies that employ spherically symmetric, steady, shocked accretion flows together with the light-bulb approximation. The latter has been widely used in the supernova community for the phenomenological investigation of the criteria for successful supernova explosions. In the present approach, we get rid of the steady-state condition and take into account shock wave motions instead. We have in mind a scenario in which it is not the critical luminosity but the critical fluctuation generated by hydrodynamical instabilities such as standing accretion shock instability and neutrino-driven convection in the post-shock region that determines the onset of shock revival. After confirming that the new approach indeed captures the dynamics of revived shock wave qualitatively, we then apply the method to various initial conditions and find that there is a critical fluctuation for shock revival, which can be well fit by the following formula: f crit∼ 0.8×(M in/1.4 M☉)×{1−(r sh/10 8 cm)}, where f crit denotes the critical pressure fluctuation normalized by the unperturbed post-shock value. M in and r sh stand for the mass of the central compact object and the shock radius, respectively. The critical fluctuation decreases with the shock radius, whereas it increases with the mass of the central object. We discuss the possible implications of our results for three-dimensional effects on shock revival, which is currently controversial in the supernova community.