SHAO Colloquium in Astrophysics

Title: Quasi-Periodic Polarized Emissions from Kink Structure in Magnetized Relativistic Jets

Speaker: Xu-Fan Hu (李政道研究所)
Time: 14:00, Wednesday, 17 June 2026
Location: Meeting room, 11th floor

Abstract: Relativistic jets from active galactic nuclei are observed to be collimated on the parsec scale. When the pressure between the jet and the ambient medium is mismatched, recollimation shocks and rarefaction shocks are formed (e.g., the HST-1 in the M87 jet). In this report, I will give a brief introduction on how we perform Relativistic Magneto Hydrodynamic (RMHD) simulations to study the collimation and instability in Relativistic jets. Specifically, I will illustrate the simulation of the over-pressured magnetized jets, showing that the current-driven kink instability grows after passing the recollimation shocks. We develop the special relativistic radiative transfer techniques, revealing that the jet image differs at different frequencies: The turbulence is observed at low frequencies, while the inner structure appears at high frequencies, including bright knots and twisted kinks. We further compute the multi-wavelength spectrum energy distribution (SED) and catch the Quasi-Periodic Oscillation (QPO) signal in light curves.

CV: 胡旭凡，本科毕业于中国科大，目前为李政道研究所2023级博士研究生，导师为Yosuke Mizuno教授，主要研究涉及活动星系核光变的建模、相对论性喷流的动力学模拟与辐射机制。目前已在国际期刊 The Astrophysical Journal 及 Astronomy & Astrophysics 发表SCI论文 7 篇（其中 3 篇为第一作者）。曾获中国科大少年班学院蔷薇奖学金，入选中国科协青年科技人才培育工程博士生专项计划。