Self-sealing shells: blowouts and blisters on the surfaces of leaky wind-blown bubbles and supernova remnants
Self-sealing shells: blowouts and blisters on the surfaces of leaky wind-blown bubbles and supernova remnants
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自密封壳：泄漏的风吹气泡和超新星遗迹表面的井喷和水泡
DOI：
10.1093/mnras/stt1552
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发表时间：
2013
影响因子：
4.8
通讯作者：
J. Pittard
中科院分区：
文献类型：
--
作者：
J. Pittard
当封闭高温高压气体的致密外壳破裂时，就会发生井喷。排出的气体使外壳表面上的气泡膨胀。在这里，我们研究的增长，这样的水泡表面的风吹气泡（WBBs）和超新星遗迹（SNRs）由于壳破裂所造成的Vishniac不稳定性。在WBB上，发现气泡的最大相对尺寸（Rbstall/R）随时间线性增长，但在许多情况下，气泡半径不会超过气泡半径的20%。因此，由Vishniac不稳定性引发的井喷不太可能对泡沫的全球动力学和性质产生重大影响。SNR上的气泡的相对尺寸甚至比WBB上的更小，其中气泡仅生长到与SNR的冷壳的厚度相当的半径。然而，小尺寸的SNR井喷是，在良好的协议与观察船帆座SNR水泡。WBB和SNR气泡之间的相对尺寸差异是由于气体从WBB排出的速度高得多，这通过来自给定压力的内部气体的给定尺寸的破裂转化为更大的能量通量。如果髋臼杯破裂大于预期，则可能出现更大的水泡。我们预计观察到的SNR壳的速度结构将受到水泡的存在，直到壳不再容易破裂，因为水泡的初始膨胀比壳的持续膨胀更快。
Blowouts can occur when a dense shell confining hot, high-pressure gas ruptures. The venting gas inflates a blister on the surface of the shell. Here we examine the growth of such blisters on the surfaces of wind-blown bubbles (WBBs) and supernova remnants (SNRs) due to shell rupture caused by the Vishniac instability. On WBBs the maximum relative size of the blister (Rbstall/R) is found to grow linearly with time, but in many cases the blister radius will not exceed 20 per cent of the bubble radius. Thus blowouts initiated by the Vishniac instability are unlikely to have a major effect on the global dynamics and properties of the bubble. The relative size of blisters on SNRs is even smaller than on WBBs, with blisters only growing to a radius comparable to the thickness of the cold shell of SNRs. The small size of the SNR blowouts is, however, in good agreement with observations of blisters in the Vela SNR. The difference in relative size between WBB and SNR blisters is due to the much higher speed at which gas vents out of WBBs, which translates into a greater energy flux through a rupture of a given size from interior gas of a given pressure. Larger blisters are possible if shell ruptures are bigger than expected. We expect the observed velocity structure of SNR shells to be affected by the presence of blisters until the shell is no longer susceptible to ruptures, since the initial expansion of blisters is faster than the ongoing expansion of the shell.