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.

arXiv comment5 pages, 4 figures, accepted for publication in ApJL. Small corrections

References in corpus (29)

• BL Lac Objects in the Synchrotron Proton Blazar Model
• A low level of extragalactic background light as revealed by gamma-rays from blazars
• Structured jets in TeV BL Lac objects and radiogalaxies
• Fast variability of TeV gamma-rays from the radio galaxy M 87
• VHE Gamma-Ray Observation of the Crab Nebula and its Pulsar with the MAGIC telescope
• VLBI Observations of a Complete Sample of Radio Galaxies. 10 Years Later
• Implementation of the Random Forest Method for the Imaging Atmospheric Cherenkov Telescope MAGIC
• New limits on the density of the extragalactic background light in the optical to the far-infrared from the spectra of all known TeV blazars
• Production of TeV gamma-radiation in the vicinity of the supermassive black hole in the giant radiogalaxy M87
• Is the Giant Radio Galaxy M87 a TeV Gamma-Ray Emitter?
• Spine-sheath layer radiative interplay in subparsec-scale jets and the TeV emission from M87
• Orbital Motion in the Radio Galaxy 3C 66B: Evidence for a Supermassive Black Hole Binary
• Formation of hard VHE gamma-ray spectra of blazars due to internal photon-photon absorption
• Blazar Gamma-Rays, Shock Acceleration, and the Extragalactic Background Light
• Improving the performance of the single-dish Cherenkov telescope MAGIC through the use of signal timing
• Hard TeV spectra of blazars and the constraints to the IR intergalactic background
• Discovery of Very High Energy gamma-rays from 1ES 1011+496 at z=0.212
• Very High Energy Gamma-Ray Observations of a Strong Flaring Activity in M87 in 2008 February
• Unfolding of differential energy spectra in the MAGIC experiment
• Discovery of Very High Energy $\gamma$-Rays from Markarian~180 Triggered by an Optical Outburst
• Month-Timescale Optical Variability in the M87 Jet
• Synoptic studies of seventeen blazars detected in very high-energy gamma-rays
• Constraints on the Very High Energy Emission from BL Lacertae Objects
• Signal Reconstruction for the MAGIC Telescope
• Observations of the BL Lac Object 3C 66A with STACEE
• The drive system of the Major Atmospheric Gamma-ray Imaging Cherenkov Telescope
• Redshift Limits of BL Lacertae Objects from Optical Spectroscopy
• 3C66B as a TeV radiogalaxy
• Intergalactic absorption and blazar gamma-ray spectra

Cited by in corpus (41)

• Blazars as Ultra-High-Energy Cosmic-Ray Sources: Implications for TeV Gamma-Ray Observations
• Discovery of very high energy gamma-ray emission from Centaurus A with H.E.S.S
• Hints of the existence of Axion-Like-Particles from the gamma-ray spectra of cosmological sources
• A new interpretation of the gamma-ray observations of active galactic nuclei
• Fermi Large Area Telescope View of the Core of the Radio Galaxy Centaurus A
• Indications for a pair-production anomaly from the propagation of VHE gamma-rays
• Role of line-of-sight cosmic ray interactions in forming the spectra of distant blazars in TeV gamma rays and high-energy neutrinos
• Dark Matter and Fundamental Physics with the Cherenkov Telescope Array
• Fermi observations of TeV-selected AGN
• Long-term optical monitoring of TeV emitting Blazars
• MAGIC gamma-ray and multifrequency observations of flat spectrum radio quasar PKS 1510-089 in early 2012
• VERITAS Observations of a Very High Energy Gamma-ray Flare from the Blazar 3C 66A
• Sub-PeV Neutrinos from TeV Unidentified Sources in the Galaxy
• The RINGO2 and DIPOL Optical Polarisation Catalogue of Blazars
• MAGIC observations and multifrequency properties of the Flat Spectrum Radio Quasar 3C 279 in 2011
• Importance of axion-like particles for very-high-energy astrophysics
• Discovery of VHE gamma-ray emission from the BL Lac object B3 2247+381 with the MAGIC telescopes
• X-ray spectral studies of TeV gamma-ray emitting blazars
• Observations of the Blazar 3C 66A with the MAGIC Telescopes in Stereoscopic Mode
• Discovery of very high energy gamma-ray emission from the blazar 1ES 1727+502 with the MAGIC Telescopes
• Modeling the hard TeV spectra of blazars 1ES 0229+200 and 3C 66A with an internal absorption scenario
• Redshift determination of the BL Lac object 3C66A by the detection of its host galaxy cluster at $z=0.340$
• Multi-color optical monitoring of ten blazars from 2005 to 2011
• Signature of Inverse Compton emission from blazars
• Redshifts of distant blazar limited by Fermi and VHE $\gamma$-ray observations
• MAGIC upper limits to the VHE gamma-ray flux of 3C454.3 in high emission state
• 3C66B as a TeV radiogalaxy
• Effect of axion-like particles on the spectrum of the extragalactic gamma-ray background
• Expectation on Observation of Supernova Remnants with the LHAASO Project
• Probing the Scale of ALP Interactions with Fermi Blazars
• A general relativistic external Compton-scattering model for TeV emission from M87
• Can Turbulence Dominate Depolarization of Optical Blazars?
• Proper Motion of the Sub-Parsec Scale Jet in the Radio Galaxy 3C 66B
• Mechanism of very high energy radiation in BL Lacertae object 3C 66A
• 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
• Connection Between Optical and VHE Gamma-ray Emission in Blazar Jets
• Axion searches with Fermi and IACTs
• Results from MAGIC Observations of Extragalactic Relativistic Sources
• Physics Insights from Recent MAGIC AGN Observations