A1 Refereed original research article in a scientific journal

The ambiguous AT2022rze: changing-look AGN mimicking a supernova in a merging galaxy system




AuthorsPessi, Priscila; Lunnan, R.; Sollerman, Jesper; Yan, L.; Le Reste, A.; Yao, Y.; Nordblom, S.; Sharma, Y.; Gilfanov, M.; Sunyaev, R.; Schulze, S.; Johansson, J.; Gangopadhyay, A.; Fremling, C.; Tristram, K.; Hayes, Matthew; Fransson, C.; Hu, Yan; Brennan, S. J.; Rose, S.; De, K.; Hinds, K-Ryan; Liu, Chang; Miller, Adam; Qin, Yu-Jing; Charalampopoulos, P.; Gkini, A.; Graham, Matthew; Gutiérrez, Claudia; Mattila, Seppo; Nagao, Takashi; Perez-Fournon, I; Poidevin, F.; Bloom, J. S.; Brugger, J.; Chen, T. X.; Kasliwal, Mansi ; Masci, F. J.; Purdum, J. N.

PublisherOxford University Press

Publication year2025

Journal:Monthly Notices of the Royal Astronomical Society

Volume542

Issue4

First page 3354

Last page3372

ISSN0035-8711

eISSN1365-2966

DOIhttps://doi.org/10.1093/mnras/staf1433

Web address https://doi.org/10.1093/mnras/staf1433

Self-archived copy’s web addresshttps://research.utu.fi/converis/portal/detail/Publication/505230897


Abstract

AT2022rze is a luminous, ambiguous transient located south-east of the geometric centre of its host galaxy at redshift z = 0 . 08. The host appears to be formed by a merging galaxy system. The observed characteristics of AT2022rze are reminiscent of active galactic nuclei (AGNs), tidal disruption events, and superluminous supernovae. The transient reached a peak absolute magnitude of −20.2 ±0.2 mag, showing a sharp rise ( trise , 1 / e = 27 . 5 ±0 . 6 d) followed by a slow decline ( tdec , 1 / e = 382 . 9 ±0 . 6). Its bumpy light curve and narrow Balmer lines indicate the presence of gas (and dust). Its light curve shows rather red colours, indicating that the transient could be affected by significant host extinction. The spectra reveal coronal lines, indicative of high-energy (X-ray/UV) emission. Archival data reveal no prior activity at this location, disfavouring a steady-state AGN, although an optical spectrum obtained prior to the transient is consistent with an AGN classification of the host. Based on this, we conclude that the transient most likely represents a changing-look AGN at the centre of the smallest component of the merging system.


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Funding information in the publication
https://academic.oup.com/mnras/article/542/4/3354/8242739#531721970


Last updated on 2025-07-11 at 12:24