RUI: Observational Studies of Supernova Remnants and the Interstellar Medium

温克勒超新星是大质量恒星结束生命的灾难性事件。一颗典型的超新星爆炸在几秒钟内释放出大约1044焦耳的能量，相当于太阳在其整个生命周期中所消耗的能量。如此巨大的能量释放对发生超新星的星系的动力学有着深远的影响；例如，超新星的冲击波在遇到密集的星际云时可以触发恒星形成。超新星负责宇宙中大多数重元素的产生和分布。元素周期表上从氦到铁的几乎所有元素都是在大质量恒星的核合成中形成的，并通过超新星爆炸分布在宇宙各地。这个项目的总体目标是更好地理解超新星是如何爆炸的，它们巨大的能量释放是如何影响宿主星系的，以及它们是如何促进宇宙的化学演化的。对于年轻的超新星残余物（SNRs），可以识别出来自超新星的未受污染的抛射物，光谱学将导致这些恒星核心碎片的化学丰度，并提供产生它们的核合成过程的信息。目前的模型表明超新星爆炸一定是不对称的；对幸存的喷射物节和反冲的中子星的速度测量可以检验这些理论。在更古老、更大的大量残留物中，膨胀的激波可以探测星际介质的密度、结构和丰度。在氢、氧和硫的发射线中看到的几十个残留物的图像将被汇编成snr的发射在线地图集。这些光学图像可以在网上和印刷形式中广泛获取，它们将为公众生动地展示塑造宇宙的动态过程，并将作为天文学家与x射线、无线电和其他波长的图像相结合的资源。麦哲伦云发射在线巡天（MCELS）利用位于塞罗托洛洛美洲天文台（CTIO）的0.6米施密特望远镜，对离我们最近的大麦哲伦云和小麦哲伦云进行了成像。它提供的深发射在线图像将被分析，以研究所有尺度的星际介质——从微小的行星状星云，到超新星遗迹，再到由多次超新星爆炸雕刻的巨大超级壳——不受阻挡我们在银河系中视线的尘埃的阻碍。对这些整个星系的统计研究，以及对其中单个物体的详细探测，将与CTIO和其他地方的天文学家合作进行。本科生将在本研究的所有阶段发挥不可或缺的作用，这是本项目最重要的广泛影响。早在他们的第一年或第二年，一个有能力的学生将能够完成单个对象的图像分析。更复杂的项目将需要开发复杂的分析工具和对大型数据集的操作——足以挑战最雄心勃勃的高级荣誉候选人。对于那些选择天文学或物理学的学生，以及那些选择其他职业道路的学生来说，在本科阶段独立解决未解决的、往往是微妙的问题的经历，将使他们更好地应对未来的挑战。研究学生将通过协助米德尔伯里学院天文台的公众之夜项目，为更广泛的影响做出贡献。对一般公众产生更广泛影响的将是来自在线排放地图集和MCELS的引人注目的图像，这些图像可以在网络上获得，并在通俗文学中发表。该奖项是在美国国家科学基金会本科院校研究（RUI）项目的支持下颁发的

AST 0307613Winkler Supernovae are the cataclysmic events in which massive stars end their lives. A typicalsupernova explosion releases in a few seconds an energy of about 1044 Joules, comparable to what the Sun will expend throughout the entire course of its lifetime. Such a prodigious release ofenergy has profound effects on the dynamics of galaxies in which supernovae occur; for example, the shock waves from supernovae can trigger episodes of star formation when they encounter denseinterstellar clouds. Supernovae are responsible for the production and distribution of most of the heavy elements in the universe. Virtually all the elements from helium to iron on the periodic table were forged by nucleosynthesis in the cores of massive stars and distributed around the cosmos through supernova explosions. The overall goal of this project, led by Dr. Frank Winkler at Middlebury College, is to achieve a better understanding of how supernovae explode, how their prodigious energy release affects their host galaxies, and how they contribute to the chemical evolution of the Universe. For young supernova remnants (SNRs) where uncontaminated ejecta from the supernova can be identified, spectroscopy will lead to chemical abundances of these fragments of the stellar core and provide information about the nucleosynthesis processes that produced them. Current models suggest that supernova explosions must be asymmetric; proposed velocity measurements of surviving knots of ejecta and of recoiling neutron stars can test these theories. In the far more numerous remnants that are older and larger, expanding shocks can probe the density, structure, and abundances of the interstellar medium. Images of dozens of remnants as seen in emission lines of hydrogen, oxygen, and sulfur will be compiled into an Emission-Line Atlas of SNRs. Widely available on-line as well as in printed form, the optical images will dramatize the dynamic processes that shape the cosmos for the general public and will serve as a resource for astronomers to combine with images at X-ray, radio, and other wavelengths. The Magellanic Cloud Emission-Line Survey (MCELS) has imaged both the Large and Small Magellanic Clouds, nearest neighbor galaxies to our own, from the 0.6-m Schmidt telescope at Cerro Tololo Inter-American Observatory (CTIO). The deep emission-line images it provides will be analyzed to study the interstellar medium on all scales-from tiny planetary nebulae, to supernova remnants, to giant supershells carved by multiple supernova blasts-unimpeded by the dust that blocks our view in the Milky Way. Statistical studies of these entire galaxies, as well as detailed probes of individual objects within them, will be pursued in collaboration with astronomers at CTIO and elsewhere. The integral role that undergraduate students will play in all phases of this research is the mostimportant broader impact of this project. As early as their first or second year, an able student will be able to complete the image analysis for an individual object. More complex projects will require the development of sophisticated analytical tools and manipulation of large data sets-enough to challenge the most ambitious senior honors candidate. For those students who follow careers in astronomy or physics, as well as for those whose career paths take other directions, the experience of grappling independently with unanswered, often subtle, questions during their undergraduate years will leave them better equipped to face future challenges. Research students will themselves contribute to the broader impact by assisting in the popular program of public nights at the Middlebury College Observatory. An even broader impact for the general public will be the striking images, available over the web and published in popular literature, from the Emission-Line Atlas and the MCELS. This award is made under the auspices of the Research at Undergraduate Institutions (RUI) program at NSF.***