RUI: Completing Studies of Supernova Remnants and the Interstellar Medium

大质量恒星在灾难性的超新星爆炸中结束了它们的生命，释放出的能量与太阳在其整个100亿年的生命周期中所释放的能量一样多。如此巨大的能量释放对发生超新星的星系产生了深远的影响。例如，当冲击波遇到密集的星际云时，它们可以触发恒星形成的爆发。超新星也负责宇宙中大部分重元素的生产和分配。事实上，元素周期表上的所有元素，从碳到铁，都是在大质量恒星的核心中锻造出来的，并通过超新星爆炸分布在宇宙中。这项研究的中心主题是更好地了解(1)超新星如何爆炸，(2)超新星释放的巨大能量如何影响其所在星系，以及(3)超新星如何促进宇宙中的化学变化。研究人员和他们的学生将专注于银河系中精选的明亮超新星遗迹。此外，他们还将研究附近星系中超新星遗迹的平均影响。调查人员在米德尔伯里学院，这是一所位于佛蒙特州农村的种族多元化的大学。研究人员将与本科生合作，帮助他们发表研究结果。研究人员还将通过将在流行文献和网络上发表的《发射线地图集》中的引人注目的图像向公众宣传。该项目将特别集中在年轻的超新星残骸(SNR)上，过去30年的观测显示这些残骸有显著的扩张。在年轻的核心塌陷SNR中，未受污染的抛射物碎片可以自由扩展，图像和光谱数据将用于获得数十个幸存的抛射物结的自行和多普勒速度，以获得三维模型并探索可能的不对称性。从光谱中推断出的化学丰度可以将当前的结与它们在前体恒星的特定核心层中的起源联系在一起。在年轻的Ia型SNR中，特别是Tycho(SN1572)和RCW86(SN185)，将测量描绘其外壳的巴尔默主导的细丝的自行，以测量它们的膨胀。这两个天体中许多细丝的高信噪比光谱将使激波速度的确定成为可能，再加上本身的运动，就可以得出到这些关键天体的第一个精确距离。这位研究人员还将对整个星系中大量SNR群体的特性进行统计调查，在那里，SNR可以被隐藏在银河系中大多数SNR的前景尘埃所阻挡。研究人员和合作者将确定在过去一个世纪中拥有最多超新星的两个附近星系的SNR种群。

Massive stars end their lives in catastrophic supernova explosions, releasing as much energy as the Sun will expend throughout its entire 10-billion-year lifetime. Such an enormous energy release has profound effects on the galaxies where supernovae occur. For example, the shock waves can trigger bursts of star formation when they encounter dense interstellar clouds. Supernovae are also responsible for the production and distribution of most of the heavy elements in the Universe. Virtually all elements from carbon to iron on the periodic table were forged in the cores of massive stars and distributed around the cosmos through supernova explosions. The central themes of this research are to better understand (1) how supernovae explode, (2) how their huge energy release affects their host galaxies, and (3) how supernovae contribute to the chemical changes in the Universe. The investigator and their students will focus on selected bright supernova remnants in the Milky Way. Also, they will study the average effect of supernova remnants in the nearby galaxies. The investigator is at Middlebury College, an ethnically diverse college in rural Vermont. The investigator will work with undergraduate students and help them publish their research results. The investigator will also reach out to the public via the striking images from the Emission Line Atlas to be published in popular literature and on the web.This project will concentrate especially on young supernova remnants (SNRs), where observations made over three decades reveal significant expansion. In young core-collapse SNRs, where uncontaminated ejecta fragments are freely expanding, image and spectroscopy data will be used to obtain proper motions and Doppler velocities for dozens of surviving ejecta knots to obtain 3-dimensional models and explore possible asymmetries. Chemical abundances inferred from spectra can tie present knots to their origin in specific core layers of the progenitor stars. In young Type Ia SNRs, specifically Tycho (SN1572) and RCW86 (SN185), proper motions of Balmer-dominated filaments that delineate their outer shells will be measured to gauge their expansion. High signal-to-noise spectra of numerous filaments in both objects will enable determination of the shock velocities, which together with proper motions can yield the first precise distances to these key objects. The investigator will also statistically investigate the properties of large SNR populations in an entire galaxy, where SNRs can be seen unimpeded by the foreground dust that hides from view most SNRs in the Milky Way. The investigator and collaborators will identify the SNR populations in the two nearby galaxies which had the most supernovae in the past century.