Institutional Repository of Radio Astronomy Research Laboratory
| The Intrinsic Structure of Sagittarius A* at 1.3 cm and 7 mm | |
Cho, Ilje1,2,3; Zhao, Guang-Yao1,3; Kawashima, Tomohisa4; Kino, Motoki5,6; Akiyama, Kazunori5,7,8; Johnson, Michael D.8,9; Issaoun, Sara9,10; Moriyama, Kotaro7,11; Cheng, Xiaopeng1; Algaba, Juan-Carlos12; Jung, Taehyun1,2; Sohn, Bong Won1,2,13; Krichbaum, Thomas P.14; Wielgus, Maciek8,9; Hada, Kazuhiro11,15; Lu, Ru-Sen14,16,17; Cui, Yuzhu11,15; Sawada-Satoh, Satoko18; Shen, Zhiqiang16,17; Park, Jongho19,20; Jiang, Wu16,17; Ro, Hyunwook1,13; Yi, Kunwoo20; Wajima, Kiyoaki1; Lee, Jee Won1; Hodgson, Jeffrey21; Tazaki, Fumie11; Honma, Mareki11,15; Niinuma, Kotaro18,22; Trippe, Sascha20,23; An, Tao16; Zhang, Yingkang16; Lee, Jeong Ae1; Oh, Se-Jin1; Byun, Do-Young1,2; Lee, Sang-Sung1,2; Kim, Jae-Young1; Oh, Junghwan1,21; Koyama, Shoko19,24; Asada, Keiichi19; Wang, Xuezheng16; Cui, Lang17,25 ; Hagiwara, Yoshiaki26; Nakamura, Masanori19,27; Takamura, Mieko5; Hirota, Tomoya5; Sugiyama, Koichiro28; Kawaguchi, Noriyuki5; Kobayashi, Hideyuki11; Oyama, Tomoaki11; Yonekura, Yoshinori29; Kim, Jongsoo1; Hwang, Ju-Yeon1; Jung, Dong-Kyu1; Kim, Hyo-Ryoung1; Kim, Jeong-Sook30; Oh, Chung-Sik1; Roh, Duk-Gyoo1; Yeom, Jae-Hwan1; Xia, Bo16,17; Zhong, Weiye16,17; Li, Bin16,17; Zhao, Rongbing16,17; Wang, Jinqing16,17; Liu, Qinghui16,17; Chen, Zhong16,17
| |
| 2022-02-01 | |
| Source Publication | Astrophysical Journal
 |
| ISSN | 0004-637X |
| Volume | 926Issue:2Pages:108 |
| Contribution Rank | 25 |
| Abstract | Sagittarius A* (Sgr A*), the Galactic Center supermassive black hole (SMBH), is one of the best targets in which to resolve the innermost region of an SMBH with very long baseline interferometry (VLBI). In this study, we have carried out observations toward Sgr A* at 1.349 cm (22.223 GHz) and 6.950 mm (43.135 GHz) with the East Asian VLBI Network, as a part of the multiwavelength campaign of the Event Horizon Telescope (EHT) in 2017 April. To mitigate scattering effects, the physically motivated scattering kernel model from Psaltis et al. (2018) and the scattering parameters from Johnson et al. (2018) have been applied. As a result, a single, symmetric Gaussian model well describes the intrinsic structure of Sgr A* at both wavelengths. From closure amplitudes, the major-axis sizes are similar to 704 +/- 102 mu as (axial ratio similar to 1.19(-0.19)(+0.24)) and similar to 300 +/- 25 mu as (axial ratio similar to 1.28 +/- 0.2) at 1.349 cm and 6.95 mm, respectively. Together with a quasi-simultaneous observation at 3.5 mm (86 GHz) by Issaoun et al. (2019), we show that the intrinsic size scales with observing wavelength as a power law, with an index similar to 1.2 +/- 0.2. Our results also provide estimates of the size and compact flux density at 1.3 mm, which can be incorporated into the analysis of the EHT observations. In terms of the origin of radio emission, we have compared the intrinsic structures with the accretion flow scenario, especially the radiatively inefficient accretion flow based on the Keplerian shell model. With this, we show that a nonthermal electron population is necessary to reproduce the source sizes. |
| Keyword | magnetically arrested accretion base-line interferometry scatter-broadened image supermassive black-hole event-horizon galactic-center radio-source vlbi observations nonthermal electrons synchrotron emission Astronomy & Astrophysics |
| Subtype | Article |
| DOI | 10.3847/1538-4357/ac4165 |
| URL | 查看原文 |
| Indexed By | SCI |
| Language | 英语 |
| WOS ID | WOS:000821505000001 |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.xao.ac.cn/handle/45760611-7/5129 |
| Collection | 射电天文研究室_星系宇宙学研究团组 科研仪器设备产出_利用南山26米射电望远镜（NSRT）观测数据的文章 |
| Affiliation | 1.Korea Astronomy and Space Science Institute, Daedeok-daero 776, Yuseong-gu, Daejeon 34055, Republic of Korea; 2.University of Science and Technology, Gajeong-ro 217, Yuseong-gu, Daejeon 34113, Republic of Korea; 3.Instituto de Astrofísica de Andalucía—CSIC, Glorieta de la Astronomía s/n, E-18008 Granada, Spain; gyzhao@iaa.es; 4.Institute for Cosmic Ray Research, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582, Japan; 5.National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; 6.Kogakuin University of Technology & Engineering, Academic Support Center, 2665-1 Nakano, Hachioji, Tokyo 192-0015, Japan; 7.Massachusetts Institute of Technology Haystack Observatory, 99 Millstone Road, Westford, MA 01886, USA; 8.Black Hole Initiative at Harvard University, 20 Garden Street, Cambridge, MA 02138, USA; 9.Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA; 10.Department of Astrophysics, Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud University, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands; 11.Mizusawa VLBI Observatory, National Astronomical Observatory of Japan, 2-12 Hoshigaoka, Mizusawa, Oshu, Iwate 023-0861, Japan; 12.Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia; 13.Department of Astronomy, Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 03722, Republic of Korea; 14.Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany; 15.Department of Astronomical Science, The Graduate University for Advanced Studies (SOKENDAI), 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; 16.Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030, People’s Republic of China; 17.Key Laboratory of Radio Astronomy, Chinese Academy of Sciences, Nanjing 210008, People’s Republic of China; 18.The Research Institute for Time Studies, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, Yamaguchi 753-8511, Japan; 19.Institute of Astronomy and Astrophysics, Academia Sinica, 11F of Astronomy-Mathematics Building, AS/NTU No. 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan, R.O.C.; 20.Department of Physics and Astronomy, Seoul National University, Gwanak-gu, Seoul 08826, Republic of Korea; 21.Department of Physics and Astronomy, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul, Republic of Korea; 22.Graduate School of Sciences and Technology for Innovation, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, Yamaguchi 753-8511, Japan; 23.SNU Astronomy Research Center, Seoul National University, Gwanak-gu, Seoul 08826, Republic of Korea; 24.Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata 950-2181, Japan; 25.Xinjiang Astronomical Observatory, Chinese Academy of Sciences, Urumqi 830011, People’s Republic of China; 26.Toyo University, 5-28-20 Hakusan, Bunkyo-ku, Tokyo 112-8606, Japan; 27.National Institute of Technology, Hachinohe College, Yubinbango Aomori Prefecture Hachinohe Oaza Tamonoki character Ueno flat 16-1, 039-1192, Japan; 28.National Astronomical Research Institute of Thailand (Public Organization), 260 Moo 4, T. Donkaew, A. Maerim, Chiangmai, 50180, Thailand; 29.Center for Astronomy, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512, Japan; 30.Basic Science Research Institute, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Chungbuk 28644, Republic of Korea |
| Recommended Citation GB/T 7714 | Cho, Ilje,Zhao, Guang-Yao,Kawashima, Tomohisa,et al. The Intrinsic Structure of Sagittarius A* at 1.3 cm and 7 mm[J]. Astrophysical Journal,2022,926(2):108. |
| APA | Cho, Ilje.,Zhao, Guang-Yao.,Kawashima, Tomohisa.,Kino, Motoki.,Akiyama, Kazunori.,...&Chen, Zhong.(2022).The Intrinsic Structure of Sagittarius A* at 1.3 cm and 7 mm.Astrophysical Journal,926(2),108. |
| MLA | Cho, Ilje,et al."The Intrinsic Structure of Sagittarius A* at 1.3 cm and 7 mm".Astrophysical Journal 926.2(2022):108. |
| Files in This Item: | ||||||
| File Name/Size | DocType | Version | Access | License | ||
| Cho-2022-The Intrins（2768KB） | 期刊论文 | 出版稿 | 开放获取 | CC BY-NC-SA | View Application Full Text | |
Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.
Edit Comment