The bubble-like interior of the core-collapse supernova remnant Cassiopeia A
The bubble-like interior of the core-collapse supernova remnant Cassiopeia A
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DOI：
10.1126/science.1261949
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发表时间：
2015-01
期刊：
影响因子：
56.9
通讯作者：
D. Milisavljevic;R. Fesen
中科院分区：
文献类型：
--
作者：
D. Milisavljevic;R. Fesen
质量超过太阳8倍的恒星不会安静地消失。不对称爆炸是由它们的铁芯坍塌引起的，因为没有更多的核聚变能能够维持它们。这场恒星灾难究竟是如何发生的很难探究。Milisavljevic等人现在已经在近红外波段观察了超新星遗迹Cas A，并展示了其内部未受冲击喷出物的三维地图。气泡状结构指向湍流混合，这可能有助于我们了解其他结构无法如此详细地看到的超新星遗迹。科学，本期第526页，对超新星残骸腔的详细检查显示了内部未受冲击物质的气泡状结构。据信，大质量恒星的死亡与铁核坍塌引发的非球面爆炸有关。这些灾难性爆炸的细节仍然不确定，部分原因是由于对恒星深处不对称的观测限制有限。在这里，我们展示了年轻超新星遗迹仙后座A的近红外观测，它是IIb型核心坍缩爆炸的后代，以及它内部非激波喷出物的三维地图。残余物的内部有一个气泡状的形态，平滑地连接到残余物膨胀碎片的明亮反向冲击主壳中，并有助于解释多环结构。这种内部结构可能源于湍流混合过程，该过程鼓励向外膨胀的放射性富56ni喷射物羽流。如果这是真的，它的大量衰变产物56Fe可能仍然存在于这些内部腔中。
Burbling explosions blow metallic bubbles Stars more than about eight times the mass of the Sun don't go out quietly. Asymmetric explosions are kicked off by the collapse of their iron cores when no more fusion energy can sustain them. Exactly how this stellar catastrophe proceeds is difficult to probe. Milisavljevic et al. have now peered into the supernova remnant Cas A in the near-infrared and present a three-dimensional map of its interior unshocked ejecta. The bubble-like structure points to turbulent mixing, which may help us understand other supernova remnants whose structure cannot be seen in such detail. Science, this issue p. 526 Detailed examination of a supernova’s debris cavity shows bubble-like structures of unshocked material within. The death of massive stars is believed to involve aspheric explosions initiated by the collapse of an iron core. The specifics of these catastrophic explosions remain uncertain, due partly to limited observational constraints on asymmetries deep inside the star. Here we present near-infrared observations of the young supernova remnant Cassiopeia A, descendant of a type IIb core-collapse explosion, and a three-dimensional map of its interior unshocked ejecta. The remnant’s interior has a bubble-like morphology that smoothly connects to and helps explain the multiringed structures seen in the remnant's bright reverse-shocked main shell of expanding debris. This internal structure may originate from turbulent mixing processes that encouraged outwardly expanding plumes of radioactive 56Ni-rich ejecta. If this is true, substantial amounts of its decay product, 56Fe, may still reside in these interior cavities.