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The ablation of gas clouds by blazar jets
(EDP Sciences, 2020)
Context. Flaring activity in blazars can last for vastly different timescales, and it may be the result of density enhancements in the jet flow that result from the intrusion of an interstellar cloud into the jet.
Aims. ...
Probing the emission mechanism and magnetic field of neutrino blazars with multiwavelength polarization signatures
(IOP Publishing, 2019)
The characteristic two-component blazar spectral energy distribution (SED) can be of either leptonic and/or hadronic origins. The potential association of the high-energy neutrino event IceCube-170922A with the flaring ...
Detection of large-scale Ly α absorbers at large angles to the radio axis of high-redshift radio galaxies using SOAR
(Oxford Univ Press, 2018)
We present an investigation of the properties of the extended Ly α halo and the large-scale
H I absorbing structures associated with five high-redshift radio galaxies at z > 2, using the
Goodman long-slit spectrograph ...
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 ...
Fermi/LAT counterparts of IceCube neutrinos above 100 TeV
(EDP Sciences, 2018)
The IceCube Collaboration has published four years of data and the observed neutrino flux is significantly in excess of the expected atmospheric background. Due to the steeply falling atmospheric background spectrum, events ...
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 ...
EBL inhomogeneity and hard-spectrum gamma-ray sources
(IOP Publishing, 2017)
The unexpectedly hard very-high-energy (VHE; E > 100 GeV) γ-ray spectra of a few distant blazars have been interpreted as evidence of a reduction of the γγ opacity of the universe due to the interaction of VHE γ-rays with ...
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 ...
Long-term X-ray variability characteristics of the narrow-line Seyfert 1 galaxy RE J1034+396
(Oxford Univ Press, 2018)
We present the results of our study of the long-term X-ray variability characteristics of the narrow-line Seyfert 1 galaxy RE J1034+396. We use data obtained from the AstroSat satellite along with light curves obtained ...
H.E.S.S. discovery of very high energy γ-ray emission from PKS 0625−354
(Oxford Univ Press, 2018)
PKS 0625−354 (z = 0.055) was observed with the four High Energy Stereoscopic System (H.E.S.S.) telescopes in 2012 during 5.5 h. The source was detected above an energy threshold of 200 GeV at a significance level of 6.1σ. ...