Fermi-LAT detection of enhanced gamma-ray activity from the BCU MG2 J164800+2224
ATel #17701; Ettore Bronzini (INAF-OAS), on behalf of the Fermi Large Area Telescope Collaboration
on 25 Feb 2026; 21:06 UT
Credential Certification: Ettore Bronzini (ettore.bronzini@inaf.it)
Subjects: Gamma Ray, >GeV, AGN, Blazar
The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed enhanced gamma-ray activity from a source positionally consistent with the Blazar Candidate of Uncertain Type MG2 J164800+2224, also known as 4FGL J1648.0+2221 (Abdollahi et al. 2022, ApJS, 260, 53), R.A. = 252.00640 deg, Dec. = +22.40921 deg (J2000; Petrov&Taylor 2011, AJ, 142, 3, 89), and redshift z=0.822 (The Sloan Digital Sky Survey 2017, ApJS, 233, 25).
Preliminary analysis indicates that this source was in an elevated gamma-ray emission state on February 24th, 2026Â , with a daily averaged gamma-ray flux (E>100MeV) of (0.4+/-0.1) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only). This corresponds to a flux increase of a factor of about 60 relative to the average flux reported in the fourth data release of the fourth Fermi-LAT catalog (4FGL-DR4, Ballet et al. 2023, arXiv:2307.12546). The corresponding photon index is 2.4+/-0.3, and is consistent with the 4FGL-DR4 value of 2.6+/-0.1 within the uncertainties. The Fermi-LAT Collaboration has previously reported a flaring activity from this source in ATel #16227.
Because Fermi normally operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. A preliminary light curve for BCU MG2 J164800+2224 can be accessed via the Fermi-LAT Light-Curve Repository. We encourage multifrequency observations of this source. For this source, the Fermi-LAT contact person is Adithiya Dinesh (adinesh@ucm.es).
The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
