Please use this identifier to cite or link to this item:
http://hdl.handle.net/20.500.12386/35571
Title: | The radio detection and accretion properties of the peculiar nuclear transient AT 2019avd | Authors: | Wang, Yanan BALDI, Ranieri Diego del Palacio, Santiago Guolo, Muryel Yang, Xiaolong Zhang, Yangkang Done, Chris Castro Segura, Noel Pasham, Dheeraj R Middleton, Matthew Altamirano, Diego Gandhi, Poshak Qiao, Erlin Jiang, Ning Yan, Hongliang GIROLETTI, Marcello MIGLIORI, Giulia McHardy, Ian PANESSA, Francesca Jin, Chichuan Shen, Rongfeng Dai, Lixin |
Issue Date: | 2023 | Journal: | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY | Number: | 520 | Issue: | 2 | First Page: | 2417 | Abstract: | AT 2019avd is a nuclear transient detected from infrared to soft X-rays, though its nature is yet unclear. The source has shown two consecutive flaring episodes in the optical and the infrared bands, and its second flare was covered by X-ray monitoring programs. During this flare, the UVOT/Swift photometries revealed two plateaus: one observed after the peak and the other one appeared ~240 d later. Meanwhile, our NICER and XRT/Swift campaigns show two declines in the X-ray emission, one during the first optical plateau and one 70-90 d after the optical/UV decline. The evidence suggests that the optical/UV could not have been primarily originated from X-ray reprocessing. Furthermore, we detected a timelag of ~16-34 d between the optical and UV emission, which indicates the optical likely comes from UV reprocessing by a gas at a distance of 0.01-0.03 pc. We also report the first VLA and VLBA detection of this source at different frequencies and different stages of the second flare. The information obtained in the radio band - namely a steep and a late-time inverted radio spectrum, a high brightness temperature and a radio-loud state at late times - together with the multiwavelength properties of AT 2019avd suggests the launching and evolution of outflows such as disc winds or jets. In conclusion, we propose that after the ignition of black hole activity in the first flare, a super-Eddington flaring accretion disc formed and settled to a sub-Eddington state by the end of the second flare, associated with a compact radio outflow. | URI: | http://hdl.handle.net/20.500.12386/35571 | URL: | https://academic.oup.com/mnras/article/520/2/2417/6985648 http://arxiv.org/abs/2212.08453v2 |
ISSN: | 0035-8711 | DOI: | 10.1093/mnras/stad101 | Bibcode ADS: | 2023MNRAS.520.2417W | Fulltext: | open |
Appears in Collections: | 1.01 Articoli in rivista |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
stad101.pdf | PDF editoriale | 2.27 MB | Adobe PDF | View/Open |
Page view(s)
36
checked on Feb 17, 2025
Download(s)
3
checked on Feb 17, 2025
Google ScholarTM
Check
Altmetric
Altmetric
Items in DSpace are published in Open Access, unless otherwise indicated.