Supernova 1987A: Versatile Astrophysical Tool & Unique Opportunity to Study SNR Formation

超新星1987A是近四个世纪以来距离最近的超新星，也是研究最深入的超新星，随着爆炸喷出的物质撞击到这颗恒星在过去100万年里脱落的星周包层，它正在迅速变成超新星残骸。在这个项目中，将结合档案、光学、红外线和紫外线项目以及空间研究来跟踪这一过程。克罗茨博士之前对爆炸前星云的三维结构、速度、密度和成分进行的观测，将确定爆炸前星云的性质和产生它的质量损失过程，而对碰撞中产生的X射线和极端紫外线通量激发该星云的新观测，将使克罗茨博士能够再次对其进行分析。除了这项对超新星遗迹的研究外，克罗茨博士还将继续利用超新星爆炸的光回波来探索剑鱼座30号恒星形成区的星际介质，研究超新星爆炸产生的紫外线脉冲通过前驱恒星表面的回波，并准确地确定到大麦哲伦星云的距离--银河外距离阶梯上的一个基本梯级。克罗茨还将探索他的图像差分软件在生物医学成像中的应用--特别是用于跟踪超新星回波外观变化的图像处理算法如何跟踪其他数据集的变化，尤其是用于早期检测癌细胞生长的CT扫描染料测试。光回声数据还将用于渲染和动画，作为几个公开展示光回声揭示的迷人结构的一部分。

Supernova 1987A, the closest supernova seen in nearly four centuries, and the most intensely studied, is rapidly turning into a supernova remnant as the ejecta from the explosion now strikes the circumstellar envelope shed by the star over the last million years. In this project, this process will be followed using a combination of archival, optical, infra-red and ultra-violet programs, plus space-based studies. Previous observations taken by Dr. Crotts of the three dimensional structure, velocities, density and composition will establish the nature of the pre-explosion nebula and the mass loss processes that created it, while new observations of the excitation of this nebula by the X-ray and extreme ultra-violet flux created in the collision will enable Dr. Crotts to re-analyze it once more. In addition to this study of a supernova remnant, Dr. Crotts will continue to use light echoes from the supernova explosion to explore the interstellar medium in the 30 Doradus star-formation region, to study the echo of the ultra-violet pulse from supernova shock breakout through the progenitor star's surface, and accurately to determine the distance to the Large Magellanic Cloud - a fundamental rung on the extragalactic distance ladder. Dr. Crotts will also explore the application of his image differencing software to biomedical imaging - specifically how the image processing algorithms used to trace changes in the appearance of supernova echoes can track changes in other data sets, prominently CT-scan dye tests used for early detection of cancerous growths. The light echo data will also be used in renderings and animations as part of several public-access demonstrations of the fascinating structures revealed by light echoes.