Detection of enhanced very-high-energy gamma-ray emission from Markarian 421
ATel #16533; Thomas Tavernier, in the behalf of SST-1M Consortium
on 15 Mar 2024; 16:55 UT
Credential Certification: Thomas Tavernier (tavernier@fzu.cz)
Subjects: Gamma Ray, TeV, VHE, AGN, Blazar
Referred to by ATel #: 16537
We report a significant increase in gamma-ray flux from Markarian 421 above 2 TeV. This observation was conducted through stereo observations using the 2 SST-1M IACTs currently in commissioning at the Ondrejov Observatory.
The observations extends from 13 March 2024 20:53 to 00:20 UTC resulting in a livetime of approximately 3.3 hours, during which a detection significance of 6.8 sigma was achieved with notable excess up to 7 TeV.
The observed flux from Markarian 421 reached levels typically observed from the Crab Nebula, suggesting a substantial increase compared to our previous baseline.
Preliminary analysis yields a measured spectral index above 2 TeV of 3.4 ± 0.5 (stat).
Observations on Markarian 421 will continue during subsequent nights, depending on weather conditions. Multi-wavelength observations are encouraged.
The SST1M instrument is a pair of small-sized IACTs designed to detect gamma rays in the energy range of 1 to 300 TeV [1]. It is the product of a collaboration between institutions across Poland, Switzerland and The Czech Republic.
[1] PoS(ICRC2023)592
