arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0705.0057astro-ph
收藏

超新星1987 A高分辨率射电成像的15年

Fifteen Years of High-Resolution Radio Imaging of Supernova 1987A

B. M. Gaensler, L. Staveley-Smith, R. N. Manchester, M. J. Kesteven, L. Ball, A. K. Tzioumis

备注：
10 pages, including 7 b/w + 1 color embedded EPS figures; uses aipproc.cls . To appear in "Supernova 1987A: Twenty Years After: Supernovae and Gamma-Ray Bursters", edited by S. Immler, K. W. Weiler and R. McCray, American Institute of Physics, New York, 2007, in press. Updated figure 2
发表信息：
AIP Conf.Proc.937:86-95,2007
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

大麦云星云中的超新星1987 A提供了一个非常详细的核心坍塌爆炸后的景象。超新星喷出物最初以超过10%的光速向外滑行，但在1990年，当它们开始遇到由祖星喷出的致密星周物质时，被观察到迅速减速。由此产生的冲击波随后产生了稳定增亮的射电同步辐射，这被澳大利亚望远镜紧凑阵列（ATCA）分解成一个膨胀的边缘增亮壳层。在这里，我们提出了15年的ATCA成像超新星1987 A，在有效的角分辨率为0.4角秒。我们发现，在此期间，无线电残骸加速膨胀，从1992年的约3600公里/秒到2006年底的约5200公里/秒。已公布的演化中的X射线壳层的直径比相应的射电值小约15%，但同时对射电和X射线数据进行傅立叶分析消除了这种差异，并得出两个波段的壳层的当前直径约为1.7弧秒。在所有ATCA时期的射电图像中可以看到不对称的亮度分布：东部和西部边缘的通量高于北部和南部区域，这表明大部分射电辐射来自系统的赤道面，那里的祖星的星周风被认为是密集的。东瓣比西瓣更亮，离超新星位置也更远，这表明超新星喷出物的初始分布存在额外的不对称性。

英文摘要：

Supernova 1987A in the Large Magellanic Cloud provides a spectacularly detailed view of the aftermath of a core-collapse explosion. The supernova ejecta initially coasted outward at more than 10% of the speed of light, but in 1990 were observed to decelerate rapidly as they began to encounter dense circumstellar material expelled by the progenitor star. The resulting shock has subsequently produced steadily brightening radio synchrotron emission, which is resolved by the Australia Telescope Compact Array (ATCA) into an expanding limb-brightened shell. Here we present 15 years of ATCA imaging of Supernova 1987A, at an effective angular resolution of 0.4 arcsec. We find that the radio remnant has accelerated in its expansion over this period, from approx 3600 km/s in 1992 to approx 5200 km/s at the end of 2006. The published diameters of the evolving X-ray shell have been ~15% smaller than the corresponding radio values, but a simultaneous Fourier analysis of both radio and X-ray data eliminates this discrepancy, and yields a current diameter for the shell in both wave-bands of approx 1.7 arcsec. An asymmetric brightness distribution is seen in radio images at all ATCA epochs: the eastern and western rims have higher fluxes than the northern and southern regions, indicating that most of the radio emission comes from the equatorial plane of the system, where the progenitor star's circumstellar wind is thought to be densest. The eastern lobe is brighter than and further from the supernova site than the western lobe, suggesting an additional asymmetry in the initial distribution of supernova ejecta.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑