S40954+65喷流的高分辨率观测研究  

High Resolution Observation Study of S40954+65 Radio Jet

作　　者：王玕 路如森[1,4] 沈志强[1,4] 江悟[1,4] 黄磊[1,5] 赵杉杉[1] 闫玺[1,3] 程远 WANG Gan;LU Ru-sen;SHEN Zhi-qiang;JIANG Wu;HUANG Lei;ZHAO Shan-shan;YAN Xi;CHENG Yuan(Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 200030,China;ShanghaiTech University,Shanghai 201210,China;University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Radio Astronomy,Chinese Academy of Sciences,Nanjing 210008,China;Key Laboratory for Research in Galaxies and Cosmology,Chinese Academy of Sciences,Shanghai 200030,China)

机构地区：[1]中国科学院上海天文台,上海200030 [2]上海科技大学,上海201210 [3]中国科学院大学,北京100049 [4]中国科学院射电天文重点实验室,南京210008 [5]中国科学院星系宇宙学重点实验室,上海200030

出　　处：《天文学进展》2023年第2期257-268,共12页Progress In Astronomy

基　　金：国家自然科学基金(11933007);中科院基础前沿科学研究计划从0到1原始创新项目(ZDBS-LY-SLH011);上海市基础研究特区计划(JCYJ-SHFY-2021-013)。

摘　　要：S40954+65是一个典型的BL Lac天体,观测表明,其射电、光学和γ射线波段的辐射具有准同步耀变现象。利用美国甚长基线干涉阵列VLBA对该源分别在2018年6月和2019年11月进行多波段观测,发现其射电核的流量密度谱有明显变化。通过同步自吸收机制,得到射电核心磁场强度为(3.3±0.9)×10^(−4)T。通过分析2017年5月―2021年5月期间VLBA 43 GHz观测的归档数据,发现2个明显的喷流运动成分和靠近核心的一个静止成分。对两个运动成分分析得到喷流的视向夹角分别为5.5°和6.9°,张角为1.8°和2.4°。利用VLBA 43 GHz归档数据以及Fermi卫星4期源表(4FGL)中该源的γ射线流量,发现射电核心和γ射线在2018年10月―2021年5月间变得更加活跃,且射电核心流量变化更强。S40954+65 is a typical BL Lac object.It shows quasi-simultaneous flares in radio,optical and gamma-ray bands.We performed multi-frequency VLBI observations of S40954+65 in June 2018 and November 2019 with the Very Long Baseline Array(VLBA)in the United States.We found significant changes in the radio core spectrum during these observations and estimated the magnetic field strength in the core region to be(3.3±0.9)×10^(−4) T using a synchrotron self-absorption model.By analyzing archival VLBA 43 GHz data taken from May 2017 to May 2021,we identified three prominent jet components with two components showing apparent superluminal motion and one being stationary near the core.For these two moving jet components,the viewing angles are 5.5°and 6.9°,and the opening angles are 1.8°and 2.4°,respectively.The distribution of all jet components indicates that they move primarily along two distinct paths,consistent with previous finding of Morozova et al.Our analysis shows that both the 43 GHz core flux andγ-ray flux become more variable between October 2018 and May 2021,indicating that the VLBI core flux variations correlates with theγ-ray flux variations.

关 键 词：BL Lac天体 喷流结构 核心磁场 喷流成分 

分 类 号：P157.7[天文地球—天文学]