Polarimetric Tomography of Supernovae: Observational Probes of the Explosion Physics, Progenitor Stars, and Extragalactic Interstellar Dust

德克萨斯A M大学（TAMU）的一个研究小组将对超新星（SNe）进行详细的观测研究，因为想象力被恒星灾难的可怕景象所激发。最大亮度可以相当于十亿个太阳的亮度，物质以光速的百分之几被抛入太空。由于爆炸导致星星膨胀和变薄，来自连续层的信号揭示了星星内部的性质。可以获得对致密物体（中子星和黑洞）形成的新见解。喷出的物质富含新元素，因此SNe是宇宙核演化的主要驱动力。SNe可能会在SN加热的星系风中从星系中喷出物质。它们是星系物理演化的重要因素。最后，因为它们是如此明亮，SNe也是河外距离的精确指示器。它们测量宇宙的距离尺度，并确定宇宙膨胀的历史。 对超新星的研究也将被纳入非常成功的TAMU物理节，每年吸引全国4,000多人参加。该项目的首席研究员也是与TAMU和其他德克萨斯大学的艺术家和计算机科学家合作的关键成员，以制作天文数据和概念的3D演示文稿，包括该项目的研究成果。TAMU小组使用的分光偏振法是用断层摄影术绘制远距离超新星爆炸成分依赖的三维形状的唯一实用手段。SN光谱偏振测量领域现在正准备从构建现象学的广泛轮廓阶段过渡到对爆炸及其后果进行详细的物理驱动探测。许多最近的观察强烈指向一个双退化的祖先的情况下，至少有一个显着的一部分Ia型SNe。但喷出物在不同化学层中的表观球形度对双简并模型提出了严峻的挑战。 对Ia型超新星的早期观测应该会对母星系统和爆炸机制产生新的限制。具有高空间分辨率的成像偏振测量还将为星周和星际尘埃的性质以及河外空间和银河系中星际尘埃颗粒的比较提供新的见解。 因此，SNe的偏振测量提供了直接解决超新星宇宙学中尘埃消光问题的最佳机会。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

A research team based at Texas A&M University (TAMU) will carry out detailed observational studies of supernovae (SNe), because the imagination is fired with the awesome spectacle of stellar catastrophe. The maximum luminosity can equal that of a billion suns and matter is thrown into space at a few percent of the speed of light. As the explosion causes the star to expand and thin out, the signals from successive layers reveal the nature of the interior of the star. New insight into the formation of compact objects (neutron stars and black holes) can be acquired. The ejected matter is enriched in new elements, thus SNe are the main drivers of the nuclear evolution of the Universe. SNe may eject matter from galaxies in SN-heated galactic winds. They are an important factor in the physical evolution of galaxies. Finally, because they are so bright, SNe also serve as exquisite indicators of extragalactic distances. They measure the cosmic distance scale and determine the history of the cosmic expansion. The research on supernovae will also be integrated into the extremely successful TAMU Physics Festival, which attracts over 4,000 people nationwide each year. The principal investigator of the project is also a key member of a collaboration with artists and computer scientists in TAMU and other Texas Universities to produce 3D presentations of astronomical data and concepts, including research results from this project. Spectropolarimetry, the method used by the TAMU group, is the only practical means to tomographically map the composition-dependent 3-D shape of distant SN explosions. The field of SN spectropolarimetry is now poised to pass from the phase of constructing broad outlines of phenomenology to doing detailed physics-driven probes of the explosions and their aftermath. Many recent observations point strongly towards a double-degenerate progenitor scenario for at least a significant fraction of Type Ia SNe. But the apparent sphericity of the ejecta throughout different chemical layers poses a serious challenge to the double-degenerate models. Very early observations of SN Ia should yield new constraints on the progenitor systems and explosion mechanism. Imaging polarimetry with high spatial resolution will also provide new insights into the nature of circumstellar and interstellar dust, and the comparison of interstellar dust particles in extragalactic space and the Milky Way. Polarimetry of SNe therefore offers the best chance of directly resolving the issue of dust extinction in supernova cosmology.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.