Bright TeV gamma-ray emission from 1ES 1959+650 detected with SST-1M
ATel #18065; Thomas Tavernier, for the SST-1M Collaboration
on 21 Sep 2026; 15:34 UT
Credential Certification: Thomas Tavernier (tavernier@fzu.cz)
Subjects: Gamma Ray, TeV, VHE, AGN, Blazar
We report the detection of bright VHE gamma-ray emission above 2 TeV from the blazar 1ES 1959+650 (z=0.047) with a single SST-1M telescope.
SST-1M observations of 1ES 1959+650 were performed during the night of 18 and 19 September 2026 operating with only one of the two SST-1M telescopes. The total good-quality observation time is 2.80 hours (2 h 48 min). The source was detected at a statistical significance above 9 sigma.
The emission above 2 TeV is estimated to be close or slightly above Crab level with an estimated integral photon flux : F(E>2TeV) = (6.3 +/- 0.9) 10^-12 /cm2 /s, with significant emission extending up to several TeV.
Further observations are scheduled, and we encourage multi-wavelength observations of 1ES 1959+650 during this active state.
The SST-1M instrument consists of a pair of small-sized Cherenkov telescopes designed to detect gamma rays in the energy range from 1 to 300 TeV [1, 2]. The project is the result of a collaboration among institutions in Poland, Switzerland, and the Czech Republic.
[1] 2025JCAP...02..047A
[2] 2025A&A...699A.255A
