基于FAST的致密射电源VLBI研究

Based on the Chinese mega-science project Five-hundred-meter Aperture Spherical radio Telescope (FAST), the Very Long Baseline Interferometry study with high sensitivity on compact radio sources has been proposed during the early science stage. Three main projects are planned including the investigation of the pc-scale structure of 11 extragalactic compact radio sources with the VLBI polarimetric observations to probe the nature of the jet bending, high resolution mapping of the high redshift (z>5.7) quasars, and VLBI observations on two pulsars which were discovered by FAST to get highly accurate distance which will help improve the accuracy of their pulsar timing and radio luminosity. Through FAST VLBI observations, the compact radio sources sample will be increased, which would provide an opportunity for new project and discovery in the future.

项目依托国家重大科技基础设施500米口径球面射电望远镜（FAST），在早期观测阶段开展对致密射电源的高灵敏度甚长基线干涉（VLBI）研究。计划利用FAST作为主要单元参与的VLBI观测，对11颗河外致密射电源的精细结构开展偏振研究，探求其喷流弯曲的原理；对红移高于5.7的类星体进行高精度成图；对FAST最先发现的两颗脉冲星的距离进行准确测量，帮助修正其射电光度和削减脉冲星计时中的动力学因素。基于FAST VLBI的高灵敏度优势，将有效提升现有VLBI观测能力，扩大致密射电源的研究样本，从而为新课题和新发现提供机遇。

国家重大科技基础设施500米口径球面射电望远（FAST）已于2020年1月正式运行。射电源的高灵敏度甚长基线干涉测量（VLBI）研究是FAST的主要科学目标之一。本项目基于FAST的VLBI科学课题规划，开展了河外致密射电源精细结构的偏振研究，获得了源偏振特性和内禀的磁场结构，促进了对其演化机制的了解；利用国际VLBI阵，开展对FAST新发现的脉冲星天体测量观测，准确测量它们的距离等参数，帮助修正其射电光度和削减脉冲星计时中的动力学因素；开展FAST VLBI系统调试，获得与国内和国际射电望远镜的干涉条纹；开展对高红移类星体的观测和研究，为星系与宇宙演化提供重要信息；拓展了关于超新星遗迹的距离测量等。本项目的开展为FAST有效开展VLBI科学研究奠定了扎实的科学和技术基础，为FAST VLBI系统的正常运行和未来科学产出提供了有力支撑。项目已发表或接收9篇学术论文，培养3名研究生。