| Autor: |
Cheng, Xiaopeng, Cho, Ilje, Kawashima, Tomohisa, Kino, Motoki, Zhao, Guang-Yao, Algaba, Juan-Carlos, Kofuji, Yutaro, Lee, Sang-Sung, Lee, Jee-Won, Cheong, Whee Yeon, Jiang, Wu, Oh, Junghwan |
| Předmět: |
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| Zdroj: |
Galaxies (2075-4434); Apr2023, Vol. 11 Issue 2, p46, 15p |
| Abstrakt: |
In this work, we studied the Galactic Center supermassive black hole (SMBH), Sagittarius A* (Sgr A * ), with the KVN and VERA Array (KaVA)/East Asian VLBI Network (EAVN) monitoring observations. Especially in 13 May 2019, Sgr A * experienced an unprecedented bright near infra-red (NIR) flare; so, we find a possible counterpart at 43 GHz (7 mm). As a result, a large temporal variation of the flux density at the level ∼15.4%, with the highest flux density of 2.04 Jy, is found on 11 May 2019. Interestingly, the intrinsic sizes are also variable, and the area and major-axis size show marginal correlation with flux density with ≳2 σ. Thus, we interpret that the emission region at 43 GHz follows the larger-when-brighter relation in 2019. The possible origins are discussed with an emergence of a weak jet/outflow component and the position angle change of the rotation axis of the accretion disk in time. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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