Discovery of a very high energy gamma-ray signal from the 3C 66A/B region

Abstract

The MAGIC telescope observed the region around the distant blazar 3C 66A for 54.2 h in 2007 August-December. The observations resulted in the discovery of a gamma-ray source at energies above 150 GeV centered at celestial coordinates RA=2h23m12s and DEC=43deg0.7' (MAGIC J0223+430), coinciding with the nearby radio galaxy 3C 66B. A possible association of the excess with the blazar 3C 66A is discussed. The energy spectrum of MAGIC J0223+430 follows a power law with a normalization of (1.7+-0.3_(stat)+-0.6_(syst)) 10^(-11) TeV^(-1)cm^(-2)s^(-1) at 300 GeV and a photon index Gamma=-3.10+-0.31_(stat)+-0.2_(syst). No significant variability of the signal was found during the observation period.

5 pages, 4 figures, accepted for publication in ApJL. Small corrections

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Cited by in corpus (12)

• Hints of the existence of Axion-Like-Particles from the gamma-ray spectra of cosmological sources
• The RINGO2 and DIPOL Optical Polarisation Catalogue of Blazars
• Observations of the Blazar 3C 66A with the MAGIC Telescopes in Stereoscopic Mode
• Redshift determination of the BL Lac object 3C66A by the detection of its host galaxy cluster at $z=0.340$
• Signature of Inverse Compton emission from blazars
• MAGIC upper limits to the VHE gamma-ray flux of 3C454.3 in high emission state
• Effect of axion-like particles on the spectrum of the extragalactic gamma-ray background
• 3C66B as a TeV radiogalaxy
• Can Turbulence Dominate Depolarization of Optical Blazars?
• The `blazar sequence' in TeV band
• Search for Very High-Energy Emission from the millisecond pulsar PSR J0218+4232
• Multi-epoch, multi-frequency VLBI study of the parsec-scale jet in the blazar 3C 66A