Monitoring the Size and Flux Density of Sgr A* during the Active State in 2019 with East Asian VLBI Network
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 fi...
| Autores: | , , , , , , , , , , , |
|---|---|
| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2023 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/330564 |
| Acesso em linha: | http://hdl.handle.net/10261/330564 |
| Access Level: | acceso abierto |
| Palavra-chave: | Very long baseline interferometry (1769) Radio astronomy (1338) Galactic center (565) Supermassive black holes (1663) |
| Resumo: | 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 . 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. © 2023 by the authors. Licensee MDPI, Basel, Switzerland. |
|---|