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




Pessi, 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

2025

Monthly Notices of the Royal Astronomical Society

542

4

3354

3372

0035-8711

1365-2966

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

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

https://research.utu.fi/converis/portal/detail/Publication/505230897



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.


https://academic.oup.com/mnras/article/542/4/3354/8242739#531721970


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