X-ray illumination of the ejecta of supernova 1987A
X-ray illumination of the ejecta of supernova 1987A
复制标题
超新星 1987A 喷射物的 X 射线照明
DOI：
10.1038/nature10090
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发表时间：
2011
期刊：
影响因子：
64.8
通讯作者：
J. Wheeler
中科院分区：
文献类型：
--
作者：
J. Larsson;C. Fransson;G. Östlin;P. Gröningsson;A. Jerkstrand;C. Kozma;J. Sollerman;P. Challis;R. Kirshner;R. Chevalier;K. Heng;R. McCray;N. Suntzeff;P. Bouchet;A. Crotts;J. Danziger;E. Dwek;K. France;P. Garnavich;S. Lawrence;B. Leibundgut;P. Lundqvist;N. Panagia;C. Pun;N. Smith;G. Sonneborn;L. Wang;J. Wheeler
当一颗大质量恒星以超新星的形式爆炸时，会产生大量的放射性元素——主要是56Ni、57Ni和44ti。在最初的冲击加热闪光之后，超新星发出的暗淡的光是由于这些元素的衰变。然而，几十年后，超新星遗迹的能量来自于抛射物和周围介质之间的激波相互作用。到目前为止，还没有观测到过渡到这一阶段的现象：超新星在银河系中发生的频率太低，无法提供一个年轻的例子，而星系外的超新星通常太暗、太小。在这里，我们报告了在大麦哲伦星云中超新星SN 1987A的观测结果。从1994年到2001年，由于44Ti的放射性衰变，喷出物逐渐消失。然后流量开始增加，到2009年底增加了一倍多。我们表明，这种增加是由抛射物与周围物质相互作用时产生的x射线沉积的热的结果。随着时间的推移，x射线将进一步穿透喷射物，使我们能够分析消失恒星的结构和化学成分。
When a massive star explodes as a supernova, substantial amounts of radioactive elements—primarily 56Ni, 57Ni and 44Ti—are produced. After the initial flash of light from shock heating, the fading light emitted by the supernova is due to the decay of these elements. However, after decades, the energy powering a supernova remnant comes from the shock interaction between the ejecta and the surrounding medium. The transition to this phase has hitherto not been observed: supernovae occur too infrequently in the Milky Way to provide a young example, and extragalactic supernovae are generally too faint and too small. Here we report observations that show this transition in the supernova SN 1987A in the Large Magellanic Cloud. From 1994 to 2001, the ejecta faded owing to radioactive decay of 44Ti as predicted. Then the flux started to increase, more than doubling by the end of 2009. We show that this increase is the result of heat deposited by X-rays produced as the ejecta interacts with the surrounding material. In time, the X-rays will penetrate farther into the ejecta, enabling us to analyse the structure and chemistry of the vanished star.