从“翻译世界”到“翻译中国”---用融通中外的语言传播世界

宇宙线的发现已有百年的历史，但它的起源问题一直未解决。极高能（十的十八次方电子伏特）宇宙线和中微子的观测研究是解答 “极高能宇宙射线起源” 这一世纪难题的重要手段。目前，利用低频射电阵列探测极高能粒子的簇射过程是该领域的研究热点。本报告将介绍极高能宇宙线和中微子领域的相关研究进展，未来实验设施，基于大型中微子射电探测阵列GRAND实验介绍低频射电阵列探测高能粒子的基本原理和发展现状。

2025年4月21日（周一）10：00 地点：犀浦校区二教2539会议室 腾讯会议：414 568 756 题目: Toward Unveiling the Origins of the Milky Way Bulge through Multi-band-Messenger Sky Surveys 主讲人: Haifeng Wang Hai-Feng Wang is currently a visiting scientist at Southwest Jiaotong University in Chengdu, China. He received his Ph.D. in 2018 from the National Astronomical Observatories (Beijing), Chinese Academy of Sciences. Since then, he has held postdoctoral positions at Yunnan University in China as a LAMOST Fellow (2018–2021), the Paris Observatory in France (2021–2022), the Enrico Fermi Research Center in Rome, Italy (2022–2023), and the University of Padova in Italy (2023–2025). His research focuses on the Milky Way and the Local Universe, with particular emphasis on galactic seismology, dynamics, archaeology, interstellar matter, disk systems, and the nature of dark matter, using data analysis, modeling, and simulations. He also has a strong interest in interdisciplinary topics, including time-domain astronomy and galaxy-scale physics. Throughout his career, he has played an active role in developing and promoting the MWLUDPSG(+) research frameworks and initiatives. Abstract: The Galactic bulge hosts multiple stellar populations with distinct structural, kinematic, and chemical properties, reflecting the complex dynamical processes that shaped its formation. It is also a key region for many high-energy radiation sources. In this project, we analyze the structure, kinematics, and chemo-dynamical properties of the bulge using RR Lyrae stars from OGLE and giant stars from APOGEE and Gaia, selected based on their distances placing them in the inner Galaxy. Using ab-type RR Lyrae stars (RRabs), we identify three populations: central bulge RRabs, inner bulge RRabs, and halo/disk interlopers. The inner bulge RRabs kinematically align with the Galactic bar, while the central bulge RRabs exhibit slower rotation and lower velocity dispersion. Orbital analysis of red giant stars reveals consistent kinematic trends and a bimodal stellar density pattern, suggesting distinct star formation histories for the inner and central bulge. Our findings support the scenario in which the pseudo-bulge—formed through disk instability—is the primary component of the bulge. Model fitting favors the boxy bulge structure over the X-shaped model. Looking ahead, more precise distance measurements and detailed stellar age data will be critical for refining our understanding of disk secular evolution and halo accretion events. Additionally, we developed a new method based on the gradient boosting decision tree (GBDT) algorithm, trained on the APOKASC-2 asteroseismological catalog, to estimate stellar atmospheric parameters and ages. Using photometric age analysis, we constructed a global average age map of the Galactic bulge, which unexpectedly reveals an increase in average stellar age with galactic latitude.

双中子星并合是多信使天文的重要观测对象，而从第一性原理出发模拟其演化过程，对于解读多种观测数据是不可或缺的。其中，磁场的作用尤为关键——尽管双星并合之前的初始磁场可能较弱，但在并合过程中，各种放大机制会显著增强磁场，最终主导系统的演化，并驱动伽马射线暴、磁星风等一系列现象。本报告将从磁流体力学与数值相对论的基础出发，介绍基于第一性原理的双中子星并合模拟，解读双中子星并合过程中磁场增强的多种物理机制。报告还将探讨双星并合产生的磁星中帕克不稳定性所引发的耀变活动，以及准直喷流的形成机制。