The Matter Beyond the Ring: The Recent Evolution of SN 1987A Observed by the Hubble Space Telescope
The Matter Beyond the Ring: The Recent Evolution of SN 1987A Observed by the Hubble Space Telescope
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DOI：
10.3847/1538-4357/ab4ff2
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发表时间：
2019-10
期刊：
影响因子：
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通讯作者：
J. Larsson;C. Fransson;D. Alp;P. Challis;R. Chevalier;R. Kirshner;R. Kirshner;Stephen S. Lawrence;B. Leibundgut;P. Lundqvist;S. Mattila;K. Migotto;J. Sollerman;G. Sonneborn;J. Spyromilio;N. Suntzeff;J. Wheeler
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文献类型：
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作者：
J. Larsson;C. Fransson;D. Alp;P. Challis;R. Chevalier;R. Kirshner;R. Kirshner;Stephen S. Lawrence;B. Leibundgut;P. Lundqvist;S. Mattila;K. Migotto;J. Sollerman;G. Sonneborn;J. Spyromilio;N. Suntzeff;J. Wheeler
附近的SN 1987 A提供了年轻超新星（SN）遗迹演化的空间分辨率视图。在这里，我们提出了最近的哈勃太空望远镜成像观测SN 1987 A，我们用它来研究的喷出物，拱星赤道环（ER）的演变，并增加从ER外的材料发射。我们发现，内部的喷出物一直在以逐渐缓慢的速度增亮，西侧比东侧亮了约7000天。这是预期的，因为来自ER的X射线最有可能为喷出物发射提供动力。同时，来自ER的光发射继续随时间线性衰减。ER以680 ± 50 km s−1的速度扩张，这反映了密集热点中传播冲击的典型速度。自9500天以来，ER外出现了12个斑点和一个弥散Hα发射的边缘。新的斑点比ER中的斑点暗一个数量级以上，并且褪色更快。我们发现，ER外的斑点和漫发射可以解释为快速喷出物与高纬度物质，从ER向外环延伸的相互作用。对这种发射的进一步观测将有可能确定高纬度物质的详细几何形状，并深入了解环的形成和前身的质量损失历史。
The nearby SN 1987A offers a spatially resolved view of the evolution of a young supernova (SN) remnant. Here we present recent Hubble Space Telescope imaging observations of SN 1987A, which we use to study the evolution of the ejecta, the circumstellar equatorial ring (ER), and the increasing emission from material outside the ER. We find that the inner ejecta have been brightening at a gradually slower rate and that the western side has been brighter than the eastern side since ∼7000 days. This is expected given that the X-rays from the ER are most likely powering the ejecta emission. At the same time, the optical emission from the ER continues to fade linearly with time. The ER is expanding at 680 ± 50 km s−1, which reflects the typical velocity of transmitted shocks in the dense hot spots. A dozen spots and a rim of diffuse Hα emission have appeared outside the ER since 9500 days. The new spots are more than an order of magnitude fainter than the spots in the ER and also fade faster. We show that the spots and diffuse emission outside the ER may be explained by fast ejecta interacting with high-latitude material that extends from the ER toward the outer rings. Further observations of this emission will make it possible to determine the detailed geometry of the high-latitude material and provide insight into the formation of the rings and the mass-loss history of the progenitor.