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H.E.S.S. discovery of VHE y-rays from the quasar PKS 1510-089
(EDP Sciences, 2013)
The quasar PKS 1510-089 (z = 0.361) was observed with the H.E.S.S. array of imaging atmospheric Cherenkov telescopes during high states in the optical and GeV bands, to search for very high energy (VHE, defined as E ≥ 0.1 ...
Discovery of a new TeV gamma-ray source: Ver J0521+211
(IOP Science, 2013)
We report the detection of a new TeV gamma-ray source, VER J0521+211, based on observations made with the VERITAS imaging atmospheric Cherenkov Telescope Array. These observations were motivated by the discovery of a cluster ...
PKS 2005-489 at VHE: four years of monitoring with HESS and simultaneous multi-wavelength observations
(EDP Sciences, 2010)
Aims. Our aim is to study the very high energy (VHE; E>100 GeV) γ-ray emission from BL Lac objects and the evolution in time of their broad-band spectral energy distribution (SED).
Methods. VHE observations of the ...
The 2010 very high energy γ-ray flare and 10 years of multi-wavelength observations of M 87
(IOP Publishing, 2012)
The giant radio galaxy M 87 with its proximity (16 Mpc), famous jet, and very massive black hole ((3 – 6) × 109 M☉) provides a unique opportunity to investigate the origin of very high energy (VHE; E > 100 GeV) γ-ray ...
Discovery of VHE y-ray emission and multi-wavelength observations of the BL Lacertae object 1RXS J101015.9-311909
(EDP Science, 2012)
1RXS J101015.9 − 311909 is a galaxy located at a redshift of z = 0.14 hosting an active nucleus (called AGN) belonging to the class of bright BL Lac objects. Observations at high (HE, E > 100 MeV) and very high (VHE, E > ...
Measurement of the extragalactic background light imprint on the spectra of the brightest blazars observed with H.E.S.S.
(EDP Sciences, 2013)
The extragalactic background light (EBL) is the diffuse radiation with the second highest energy density in the Universe after the cosmic microwave background. The aim of this study is the measurement of the imprint of the ...
Radiation and polarization signatures of the 3D multizone time-dependent hadronic blazar model
(IOP Publishing, 2016)
We present a newly developed time-dependent three-dimensional multizone hadronic blazar emission model. By coupling a Fokker–Planck-based lepto-hadronic particle evolution code, 3DHad, with a polarization-dependent radiation ...
Flux upper limits for 47 AGN observed with H.E.S.S. in 2004-2011
(EDP Sciences, 2014)
Context. About 40% of the observation time of the High Energy Stereoscopic System (H.E.S.S.) is dedicated to studying active galactic nuclei
(AGN), with the aim of increasing the sample of known extragalactic very-high-energy ...
Search for extended γ-ray emission around AGN with H.E.S.S. and Fermi-LAT
(EDP Sciences, 2014)
Context. Very-high-energy (VHE; E > 100 GeV) γ-ray emission from blazars inevitably gives rise to electron-positron pair production through
the interaction of these γ-rays with the extragalactic background light (EBL). ...
Gamma-gamma absorption in the broad line region radiation fields of gamma-ray blazars
(IOP Publishing, 2016)
The expected level of γγ absorption in the Broad Line Region (BLR) radiation field of γ-ray loud Flat Spectrum Radio Quasars (FSRQs) is evaluated as a function of the location of the γ-ray emission region. This is done ...