BL Lac: A New Ultrahigh-Energy Gamma-Ray Source

Abstract

The active galactic nucleus BL Lac was observed with the Gt-48 atmospheric Cherenkov detector of the Crimean Astrophysical Observatory from July 23-September 1, 1998, in order to search for ultrahigh-energy gamma-ray (>1 TeV) emission. The object was in the field of view of the detector for more than 24 hours. The source was detected with a high level of confidence (7.2 sigma), with a flux equal to (2.1+/-0.4)x10^{-11} photons cm^{-2}s^{-1}.

7 pages, 4 figures

Cited by in corpus (12)

• Fermi observations of TeV-selected AGN
• Discovery of very high energy gamma-ray emission from the low-frequency peaked BL Lacertae object BL Lacertae
• Detection of the BL Lac Object H1426+428 at TeV Gamma Ray Energies
• Coordinated Multiwavelength Observations of BL Lacertae in 2000
• Observations of 54 Active Galactic Nuclei with the HEGRA System of Cherenkov Telescopes
• Which blazars are neutrino loud?
• The first Fermi multifrequency campaign on BL Lacertae: characterizing the low-activity state of the eponymous blazar
• Constraints on the Very High Energy Emission from BL Lacertae Objects
• Multiwavelength observations of the blazar BL Lacertae: a new fast TeV gamma-ray flare
• A Fast Very High Energy $\gamma$-ray Flare from BL Lacertae during a Period of Multiwavelength activity in June 2015
• A thirteen-year-long broadband view of BL Lac
• Optical flux and spectral variability of BL Lacertae during its historical high outburst in 2020