The Awakening of a Blazar at Redshift 2.7 Temporally Coincident with the Arrival of Cospatial Neutrino Event IceCube-201221A

Autor: Xiong Jiang, Neng-Hui Liao, Yi-Bo Wang, Rui Xue, Ning Jiang, Ting-Gui Wang
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: The Astrophysical Journal Letters, Vol 965, Iss 1, p L2 (2024)
Druh dokumentu: article
ISSN: 2041-8213
2041-8205
DOI: 10.3847/2041-8213/ad36b9
Popis: We report on multiwavelength studies of a blazar NVSS J171822+423948, which is identified as the low-energy counterpart of 4FGL J1718.5+4237, the unique γ -ray source known to be cospatial with the IceCube neutrino event IC-201221A. After a 12 yr long quiescent period undetected by Fermi-LAT, γ -ray activities with a tenfold flux increase emerge soon (a few tens of days) after the arrival of the neutrino. Associated optical flares in the Zwicky Transient Facility g , r , and i bands are observed together with elevated Wide-field Infrared Survey Explorer infrared fluxes. Synchronized variations suggest that both the γ -ray emission and the neutrino event are connected to the blazar. Furthermore, the optical spectrum reveals emission lines at a redshift z = 2.68 ± 0.01. Thus, it is the first candidate for a neutrino-emitting blazar at the redshift above 2. Discussions of theoretical constraints of neutrino production and comparisons with other candidates are presented.
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