AI 中文总结
本研究通过甚长基线干涉测量观测结合相对论磁流体动力学模拟，解释了蝎虎座BL的高偏振光学耀发源于其喷流的螺旋扫动，且喷流需重子加载才能匹配观测形态。
AI 中文摘要
blazar（耀变体）是活动星系核的一个高度可变的子类，其相对论喷流以小角度指向我们的视线，它们的变异性通常表现为多波段耀发。蝎虎座BL（BL Lac）作为耀变子类的同名天体，近期出现了有记录以来最高的线偏振光学耀发。我们通过甚长基线干涉测量观测研究该耀发的起源。分析表明，蝎虎座BL喷流的螺旋状扫动运动（已知其会表现出扭结状不稳定性）可解释观测到的流量密度峰值和偏振角旋转，最先进的相对论磁流体动力学模拟也证实了这一点。作为这些模拟的副产品，我们发现喷流的重子加载是最优复制观测到的喷流形态所必需的。
英文摘要
Blazars are a highly variable subclass of active galactic nuclei, whose relativistic jet is pointed towards our line of sight at a small angle. Their variability is often characterised by multi-band flares. BL Lacertae (BL Lac), the namesake of a blazar subclass recently exhibited the highest recorded linearly polarised optical flare. We investigate the origin of this flare via very-long-baseline interferometry observations. Our analysis shows that the sweeping, helical motion of the BL Lac jet, which is known to exhibit kink-like instabilities, can explain the observed flux density spike and polarisation angle rotation, as also confirmed by our state-of-the-art relativistic magneto-hydrodynamic simulations. As a by-product of these simulations we find that baryon loading of the jet is required to optimally replicate the observed jet morphology.
Comments9 pages, 5 figures, accepted by A&A
