Multi-wavelength variability of Mrk 421

The origin of the gamma-ray emission of the blazar Mrk 421 is still a matter of debate. We used 5.5 years of unbiased observing campaign data, obtained using the FACT telescope...耀变体（blazar）Mrk 421的γ射线辐射起源至今仍存在争议。我们使用了FACT望远镜获取的5.5年无偏观测项目数据。