East Asian VLBI Network Observations of Active Galactic Nuclei Jets: Imaging with KaVA+Tianma+Nanshan
Creators: name: Cui, Yuzhu
name: Hada, Kazuhiro
name: Kino, Motoki
name: Sohn, Bong Won
name: Park, Jongho
name: Ro, Hyun Wook
name: Sawada-Satoh, Satoko
name: Jiang, Wu
name: Cui, Lang
name: Honma, Mareki
name: Shen, Zhi Qiang
name: Tazaki, Fumie
name: An, Tao
name: Cho, Ilje
name: Zhao, Guang Yao
name: Cheng, Xiao Peng
name: Niinuma, Kotaro
name: Wajima, Kiyoaki
name: Zhang, Ying Kang
name: Kawaguchi, Noriyuki
name: Algaba, Juan Carlos
name: Koyama, Shoko
name: Hirota, Tomoya
name: Yonekura, Yoshinori
name: Sakai, Nobuyuki
name: Xia, Bo
name: Jiang, Yong Bin
name: Yu, Lin Feng
name: Gou, Wei
name: Hwang, Ju Yeon
name: Jiang, Yong Chen
name: Sun, Yun Xia
name: Jung, Dong Kyu
name: Kim, Hyo Ryoung
name: Kim, Jeong Sook
name: Kobayashi, Hideyuki
name: Lee, Jee Won
name: Lee, Jeong Ae
name: Zhang, Hua
name: Li, Guang Hui
name: Xu, Zhi Qiang
name: Li, Peng
name: Oh, Jung Hwan
name: Oh, Se Jin
name: Oh, Chung Sik
name: Oyama, Tomoaki
name: Roh, Duk Gyoo
name: Shibata, Katsunori M.
name: Guo, Wen
name: Zhao, Rong Bing
name: Zhong, Wei Ye
name: Wang, Jin Qing
name: Yang, Wen Jun
name: Yan, Hao
name: Yeom, Jae Hwan
name: Li, Bin
name: Li, Xiao Fei
name: Yuan, Jian Ping
name: Dong, Jian
name: Chen, Zhong
name: Akiyama, Kazunori
name: Asada, Keiichi
name: Byun, Do Young
name: Hagiwara, Yoshiaki
name: Hodgson, Jeffrey
name: Jung, Tae Hyun
name: Kim, Kee Tae
name: Lee, Sang Sung
name: Yi, Kunwoo
name: Liu, Qing Hui
name: Liu, Xiang
name: Lu, Ru Sen
name: Nakamura, Masanori
name: Trippe, Sascha
name: Wang, Na
name: Wang, Xue Zheng
name: Zhang, Bo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: The East Asian very-long-baseline interferometry (VLBI) Network (EAVN) is a rapidly evolving international VLBI array that is currently promoted under joint efforts among China, Japan, and Korea. EAVN aims at forming a joint VLBI Network by combining a large number of radio telescopes distributed over East Asian regions. After the combination of the Korean VLBI Network (KVN) and the VLBI Exploration of Radio Astrometry (VERA) into KaVA, further expansion with the joint array in East Asia is actively promoted. Here we report the first imaging results (at 22 and 43 GHz) of bright radio sources obtained with KaVA connected to Tianma 65-m and Nanshan 26-m Radio Telescopes in China. To test the EAVN imaging performance for different sources, we observed four active galactic nuclei (AGN) having different brightness and morphology. As a result, we confirmed that Tianma 65-m Radio Telescope (TMRT) significantly enhances the overall array sensitivity, a factor of 4 improvement in baseline sensitivity and 2 in image dynamic range compared to the case of KaVA only. The addition of Nanshan 26-m Radio Telescope (NSRT) further doubled the east-west angular resolution. With the resulting high-dynamic-range, high-resolution images with EAVN (KaVA+TMRT+NSRT), various fine-scale structures in our targets, such as the counter-jet in M87, a kink-like morphology of the 3C273 jet and the weak emission in other sources, are successfully detected. This demonstrates the powerful capability of EAVN to study AGN jets and to achieve other science goals in general. Ongoing expansion of EAVN will further enhance the angular resolution, detection sensitivity and frequency coverage of the network.
description: 19 pages, 9 figures, accepted by Research in Astronomy and Astrophysics (RAA)