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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 ...
Multi-wavelength observations of H 2356-309
(EDP Sciences, 2010)
Aims. The properties of the broad-band emission from the high-frequency peaked BL Lac H 2356–309 (z = 0.165) are investigated.
Methods. Very high energy (VHE; E > 100 GeV) observations of H 2356–309 were performed with ...
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 ...
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 ...
Cascading constraints from neutrino-emitting blazars: the case of TXS 0506+056
(IOP Publishing, 2019)
We present a procedure to generally constrain the environments of neutrino-producing sites in photomeson production models of jetted active galactic nuclei (AGNs) where any origin of the dominant target photon field can ...
Characterizing the γ-ray long-term variability of PKS 2155-304 with H.E.S.S. and Fermi-LAT
(EDP Sciences, 2017)
Studying the temporal variability of BL Lac objects at the highest energies provides unique insights into the extreme physical processes occurring in relativistic jets and in the vicinity of super-massive black holes. To ...
Gamma-ray blazar spectra with H.E.S.S. II mono analysis: the case of PKS 2155-304 and PG 1553+113
(EDP Sciences, 2017)
Context. The addition of a 28 m Cherenkov telescope (CT5) to the H.E.S.S. array extended the experiment’s sensitivityto lower energies. The lowest energy threshold is obtained using monoscopic analysis of data taken with ...
A hard gamma-ray flare from 3C 279 in 2013 December
(IOP, 2016)
The blazar 3C 279 exhibited twin γ-ray flares of similar intensity in 2013 December and 2014 April. In this work, we present a detailed multi-wavelength analysis of the 2013 December flaring event. Multi-frequency observations ...
Polarization signatures of relativistic magnetohydrodynamic shocks in the blazar emission region. I. Force-free helical magnetic fields
(IOP, 2016)
The optical radiation and polarization signatures in blazars are known to be highly variable during flaring activities. It is frequently argued that shocks are the main driver of the flaring events. However, the spectral ...