报告题目：The Heart of Darkness

　　报告人：李剑

　　报告人简介：Dr. Jian Li pursued his Ph.D. jointly at Institute of High Energy Physics, China and Institute of Space Sciences, Spain. Currently he is a Humboldt Fellow at the Deutsches Elektronen-Synchrotron DESY, Germany. Dr. Jian Li's research is mainly aimed at understanding particle acceleration process and high energy emission mechanism in Galactic sources, in a multi-wavelength context. Dr. Jian Li's research topics cover binaries, pulsars and their related nebulae, supernova remnants, and other Galactic compact objects.

　　报告摘要：Microquasars, the local siblings of extragalactic quasars, are binary systems comprising a black hole of several to tens of solar masses and a companion star. By accreting matter from their companions, microquasars launch powerful winds and jets, influencing the interstellar environment around them. Steady gamma-ray emission is expected to rise from their central objects, or from interactions between their outflows and the surrounding medium. The latter prediction was recently confirmed with the detection at the highest (TeV) energies of SS 433, one of the most interesting microquasars known. We analyzed more than ten years of GeV gamma-ray data on SS 433. Detailed scrutiny of the data reveal emission associated with a terminal lobe of one of the jets and with another position in the SS 433 vicinity, co-spatial with a gas enhancement. Both gamma-ray sources are relatively far from the central binary, and the latter shows evidence for a periodic variation at the precessional period of SS 433, linking it with the microquasar. This result challenges obvious interpretations and is unexpected from any previously published theoretical models. It provides us with a chance to unveil the particle transport from SS 433 and to probe the structure of the local magnetic field in its vicinity.

　　报告时间：2020年11月16日下午14:00

　　报告地点：紫台仙林园区2号楼311会议室

　　腾讯会议ID：139 805 041

　　腾讯会议网址：https://meeting.tencent.com/s/2A5vDuNzbUcr

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