伽玛射线暴的光学辐射监测和辐射物理性质研究

Optical survey for gamma-ray burst (GRB) phenomenon is an important field of GRB observations. It would open a new window for studying the optical emission from prior gamma-ray trigger to very early afterglow emission phase, optical emission from kilonovae associated with short GRBs, and optical emission from failed GRBs. We have set up an optical survey system that has capacity of both self-trigger and multi-wavelength observations. We will use this system and other facilities to perform campaign of optical survey and follow-up observations for GBRs and other optical transients. With our data, together with data from space-based missions and other ground-based telescopes, we will establish a broadband spectral energy distribution sample of GRBs and fit them with a spectral model composing of both multi-color blackbody radiation and synchrotron radiation to investigate the composition and radiation mechanism of the jets. We also compare the afterglow properties of GRBs from different origins and fit the multi-wavelength afterglow lightcurves with the external shock models to explore their physical properties of the radiation regions and surrounding fireballs. Basing on our comprehensive analysis for both prompt and afterglow data, we explore the possible relations among the physical parameters and observational variables through multiple regression analysis approach and their possible hints to the GRB physics. Following the progress of the SVOM mission project, we will also make simulations for both observations and data analysis, and set up the observation and data analysis team as well as international collaboration team for follow-up observations.

伽玛暴现象光学巡天是当今伽玛暴观测的一个重要方向，将为研究伽玛暴高能爆发前及暴本身到极早期余辉光学辐射、与短暴成协的Kilonovae光学辐射、失败伽玛暴光学辐射等问题打开新窗口。本项目利用具有自主触发和后随多波段观测能力的光学变源巡天系统及其它设备开展伽玛暴光学巡天观测和后随观测；集成分析我们的观测数据和空间高能卫星及其它设备观测数据，建立宽波段能谱样本，并基于多色黑体辐射模型和同步辐射模型进行拟合，研究喷流的组份和辐射机制；比较研究不同起源伽玛暴余辉观测特征, 用外激波模型拟合多波段余辉光变曲线，研究余辉辐射区和暴周环境物理性质；多维度探索暴本身和余辉各种观测量、物理量间的依赖关系，揭示其物理起源；配合SVOM等空间科学计划开展相关的模拟研究，形成后随观测的工作流程，建立起SVOM卫星科学数据分析和地基跟踪观测团队及国际合作网络。

伽玛暴等短时标时域天文现象研究是当今致密天体物理研究的重要前沿。本项目按照计划利用具有自主触发和后随多波段观测能力的光学瞬变源巡天系统及其它设备开展伽玛暴及其极早期余辉的光学巡天观测和后随观测，并在项目执行期间通过国际合作新建设1米光学望远镜加入LCO天文台组织的全球望远镜网络(LCOGT)，获得全球望远镜网络观测时间，极大地提升了观测能力，获得了具有重要科学价值的观测数据。利用这些数据，结合Swift 和Fermi 卫星观测数据，揭示伽玛暴的中心天体、喷流辐射物理和寄主星系等特性，已在Nat Comm、ApJL等主流学术期刊发表SCI收录论文80余篇(计划任务30篇)，部分观测数据分析还在进行中。针对银河系内磁星SGR 1935+2154在2020年的爆发活跃期，本项目团队参与利用射电、X射线、光学多波段的国际联测，负责光学监测，论文发表在Nature上，成果被Nature和Science杂志遴选为2020年度十大科技突破之一。项目组配合SVOM卫星科学组开展相关的模拟研究，建立后随观测的工作流程、运行机制、国际合作网络，培养SVOM卫星科学数据分析和地基跟踪观测团队。培养博士生5名、硕士生50名(已毕业取得学位23名)。项目计划任务书指定的科学研究、人才培养、团队建设和国际合作交流任务均已全面完成。