LHAASO detection of Markarian 421 in a TeV-active state
ATel #17535; Guangman Xiang (IHEP), Min Zha (IHEP), Zhiguo Yao (IHEP), Jianeng Zhou (SHAO) and Yi Xing (SHAO) report on behalf of the LHAASO Collaboration
on 10 Dec 2025; 07:47 UT
Credential Certification: Jianeng Zhou (zjn@shao.ac.cn)
Subjects: Gamma Ray, TeV, VHE, AGN, Blazar, Transient
Based on the LHAASO-WCDA real-time alert system, Markarian 421 has been detected in a very active state since September 2025.
The LHAASO-WCDA real-time alert system has reported several significant flares:
|--------------------+--------------------------+
| Time [MJD] | Flux(>1TeV)[Crab Units] |
|--------------------+--------------------------+
| 61016.97-61017.14 | 1.4 |
| 61010.82-61011.15 | 0.8 |
| 60947.99-60957.30 | 1.1 |
|--------------------+--------------------------+
We strongly encourage multi-wavelength observations.
LHAASO is a multi-purpose Extensive Air Shower (EAS) array designed to detect air showers induced by gamma rays and cosmic rays from sub-TeV energies to above 1 PeV.
