From Radio to Gamma-Rays: Interpreting the Multiwavelength Emission from Young Supernovae as a Probe of their Evolution, Progenitors, and Cosmic-Ray Acceleration

当一颗大质量恒星以超新星（SN）的形式爆炸时，爆炸产生的冲击波与恒星周围的物质相互作用，这些物质是恒星在其生命周期中被风喷出的。快速移动的冲击波将这种介质加热到高温，并将亚原子粒子加速到高能量，从而产生从低能无线电波到高能伽马射线的各种能量的辐射。芝加哥大学的一个研究小组将通过计算机模拟研究这些相互作用。他们将解释发射的辐射的特征，以推断与激波相互作用的环境介质的性质，这可能与爆炸的恒星的类型有关。这将使研究人员能够将SNe类型的多样性与它们不同的祖先恒星联系起来，帮助解决SNe和恒星天文学中的一个非常重要的问题。研究人员还将研究年轻的SNe发出的伽马射线。该项目将为本科生提供研究机会，每年夏天将选出一名高中生到芝加哥大学从事超新星研究工作。首席科学家们还将与当地学校教师合作，改善科学教育，并为非科学观众提供天文学讲座。使用复杂的发射程序，包括非平衡电离x射线计算，无线电同步加速器发射代码，使用MESA和STELLA计算机程序进行光学光曲线拟合，以及其他可用的程序，该团队将计算SN激波与环境介质相互作用产生的x射线，无线电和光学发射。该程序将用于微调星周介质结构模型，进而可用于估计祖星的质量损失特性，约束喷射参数，并确定爆炸参数。与质量损失机制的描述相结合，将使研究人员能够探测到原恒星的性质。从他们的模型中获得的详细运动学信息将用于理解SN激波中粒子加速到相对论能量，并预测伽马射线发射，这些数据可以直接与地面和天基望远镜的数据进行比较。这个项目推进了NSF宇宙大构想窗口的目标。该奖项反映了美国国家科学基金会的法定使命，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。

When a massive star explodes as a supernova (SN), the shock wave from the explosion interacts with the material around the star, which has been ejected by the wind from the star during its lifetime. The rapidly moving shock wave heats this medium to high temperatures, and accelerates subatomic particles to high energies, thus producing radiation at all energies from low-energy radio waves to very high-energy gamma rays. A research group at the University of Chicago will study these interactions through computer simulations. They will interpret the signatures of the emitted radiation to infer the nature of the ambient medium with which the shocks interact, which can be related to the type of star that exploded. This will allow the investigators to relate the wide diversity of types of SNe to their different progenitor stars, helping to solve a very important problem in SNe and stellar astronomy. The researchers will also study the gamma rays emitted from young SNe. The project will provide research opportunities for undergraduate students, and one high school student each summer will be selected to work at the University of Chicago on supernova research. The lead scientists will also work with local school teachers to improve science education and give astronomy lectures to non-scientific audiences.Using sophisticated emission routines, including non-equilibrium ionization X-ray calculations, a radio synchrotron emission code, optical light curve fitting using the computer programs MESA and STELLA, and other available routines, the team will compute the X-ray, radio and optical emission arising from the interaction of the SN shock with the ambient medium. The programs will be used to fine-tune the models of the circumstellar medium structure, which in turn can be used to estimate the mass-loss properties of the progenitor, constrain ejecta parameters, and determine explosion parameters. Coupling to descriptions of mass-loss mechanisms will allow the investigators to probe the properties of the progenitor star. The detailed kinematic information from their models will be used to understand the acceleration of particles to relativistic energies in SN shocks, and predict the gamma-ray emission, which can be directly compared with data from ground and space-based telescopes. This project advances the goals of the NSF Windows on the Universe Big Idea.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.