【7.17; Seminar】2024年粒子天体物理重点实验室系列学术报告 #36：CR propagation in the Galaxy: Insights from TeV halos, the diffuse emission, and the CR anisotropy

时间/Time：7月17日上午9: 30/Wensday, July 17th at 9:30 am

地点/Location：多学科楼312会议室/Multidisciplinary Building 312

报告人/Speaker：Gwenael Giacinti（Tsung-Dao Lee Institute）

题目/Title：CR propagation in the Galaxy: Insights from TeV halos, the diffuse emission, and the CR anisotropy

主持人/Host：刘佳 副研究员

摘要/Abstract：

Gamma-ray observations provide important information on cosmic-ray (CR) propagation in our Galaxy.

First, we discuss the TeV halos detected around Geminga and Monogem pulsars. We show that HAWC measurements of these halos place interesting constraints on the turbulent magnetic fields around these pulsars, and we examine the implications for CR transport. Moreover, we suggest that extended gamma-ray sources of a hadronic origin should exist in the data. We show that such a source may exist in the AS-gamma data at 398-1000 TeV. Observations of this new type of sources could be used to constrain the Galactic magnetic field geometry.

Then, we present a new model of anisotropic CR propagation in the Milky Way, where CRs are injected at discrete transient sources in the disc and propagated in Galactic magnetic field models. We find that the distribution of PeV CRs in our Galaxy is very clumpy, and substantially different from the smoother distribution of GeV CRs. Our findings have important implications for the calculation and interpretation of the diffuse Galactic gamma-ray fluxes at VHE.

Finally, we discuss the implications of the observed TeV-PeV cosmic-ray anisotropies on CR propagation in the ISM.

个人简介/Biography：

Gwenael Giacinti is a T. D. Lee Fellow at the Tsung-Dao Lee Institute, and a Tenure-track Associate Professor at Shanghai Jiao Tong University. Prior to that, he held postdoctoral researcher positions at the University of Oxford (United Kingdom) and at the Max Planck Institute for Nuclear Physics in Heidelberg (Germany), and earned his Ph.D. degree from Paris 7 University (France). He is interested in a number of topics in theoretical high-energy astrophysics and particle astrophysics, including cosmic-ray propagation, particle acceleration in pulsar wind nebulae, supernovae and supernova remnants, as well as gamma-ray astronomy. He is also interested in related plasma astrophysics problems, such as shock physics in the context of supernova shock breakout. He is the science working group coordinator of the Southern Wide field-of-view Gamma-ray Observatory (SWGO), and a member of the LHAASO Collaboration.