EAPSI: Demystifying the Observed Gamma Ray Burst Tracking Between the Peak Energy and Luminosity

伽马射线暴(伽马射线暴)是宇宙中能量最大的事件之一。然而，关于这些天体还有很多未知之处，比如关于它们的平行流出或喷流结构的关键信息。由于伽玛射线暴观测站无法提供与伽玛射线暴相对于探测器的方位有关的信息，因此很难推断出这一信息。这个项目将研究一种方法，通过探索时间分辨光谱峰值能量和伽玛暴探测的光曲线之间的观测跟踪的来源来确定伽玛暴几何方向的难以捉摸的信息。运行对伽玛暴辐射的模拟将使我们能够识别给定伽玛暴的跟踪关系和视角之间的相关性。该项目将在理研院与长城重弘博士一起进行。这项合作将建立在该小组以前对喷流结构进行的研究的基础上，并允许使用伽玛暴的磁流体动力学模拟，这将使我们能够充分探索峰值能量和光度之间的关系。利用后处理蒙特卡罗辐射传输程序对伽玛暴辐射传输进行了模拟。这些代码分别分散流出的每个光子，直到它自由逃逸。这使得可以在做出最小假设的情况下计算模拟伽玛暴的不同视角下的光曲线和光谱。将开发一种定量测量峰值能量与光曲线强度之间的跟踪的方法。这将有助于确定跟踪行为的特征如何随着视角的变化而变化。该奖项由东亚和太平洋暑期学院计划设立，支持一名美国研究生的暑期研究，由NSF和日本科学促进会共同资助。

Gamma Ray Bursts (GRBs) are some of the most energetic events in the universe. However, much is unknown about these objects such as critical information about the structure of their collimated outflow or jet. This information is hard to deduce due to the fact that GRB observatories are unable to provide information related to the orientation of the GRB in relation to the detector. This project will investigate a means to determining the elusive information of GRB geometrical orientation by exploring the origin of the observed tracking between the time resolved spectral peak energy and the light curve of a GRB detection. Running simulations of GRB radiation will allow us to identify a correlation between the tracking relation and the viewing angle for a given GRB. This project will be conducted at RIKEN with Dr. Shigehiro Nagataki. This collaboration will build upon previous studies conducted by the group on jet structure as well as allow for the use of magnetohydrodynamic simulations of GRBs which will allow us to fully explore the relation between the peak energy and the luminosity. The simulations of GRB radiation transfer will be conducted with post-processing Monte Carlo Radiation Transfer codes. These codes individually scatter each photon in an outflow until it freely escapes. This allows for light curves and spectra to be calculated at various viewing angles of the simulated GRB with minimal assumptions being made. A quantitative way to measure the tracking between the peak energy and the light curve intensity will be developed. This will aid in determining how the characteristics of tracking behavior changes as a function of viewing angle.This award, under the East Asia and Pacific Summer Institutes program, supports summer research by a U.S. graduate student and is jointly funded by NSF and the Japan Society for the Promotion of Science.