DAMPE detection of GeV gamma-ray flares from BL Lac
ATel #14621; Zun-Lei Xu (PMO), Kai-Kai Duan (PMO), Wei Jiang(PMO), Shi-Jun Lei (PMO), Xiang Li (PMO), Maria Munoz Salinas(UNIGE),Zhao-Qiang Shen (PMO), Meng Su (HKU/PMO), Qiang Yuan (PMO), Yi-Zhong Fan (PMO), Jin Chang (PMO), on behalf of the DAMPE collaboration
on 12 May 2021; 01:52 UT
Credential Certification: Zun-Lei Xu (xuzl@pmo.ac.cn)
Subjects: Gamma Ray, >GeV, AGN, Blazar
The DArk Matter Particle Explorer (DAMPE) has detected variable GeV gamma-ray emission from a source positionally consistent with BL Lacertae, with coordinates R.A.=22:02:43.29137 Dec.=+42:16:39.9799 (J2000; Beasley et al. 2002, ApJS, 141, 13).
The DAMPE has recorded a significant increase in the number of photons positionally consistent with the source on April 26, 2021 UT. Our analysis shows a peak daily flux of the source on that day about (6.13+/-3.01) x10^-7 photons cm^-2 s^-1 above 2 GeV, much larger than the average flux of the previous five years(~(1.55+/-0.15) x10^-8 photons cm^-2 s^-1). The daily light curve shows significant variabilities, and the flux on May 3rd is only half of the peak. The corresponding spectral index is 1.95+/-0.44, and is smaller than the five-year average value of 2.41+/-0.12. Enhanced activities of the source were also reported at the gamma-ray bands by Fermi-LAT(ATel#14583).
DAMPE is a space-borne calorimeter detector of high energy cosmic rays and gamma-rays. The detectable energy range is ~2 GeV to 10 TeV for gamma-rays. More information about DAMPE can be found at http://www.space.pmo.cas.cn/.
