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Cosmic-ray positrons from millisecond pulsars
(IOP Publishing, 2015)
Observations by the Fermi Large Area Telescope of γ-ray millisecond pulsar (MSP) light curves imply copious pair
production in their magnetospheres, and not exclusively in those of younger pulsars. Such pair cascades may ...
Discovery of very-high-energy gamma-ray emission from the vicinity of PSR J1913+1011 with HESS
(EDP Sciences, 2008)
The HESS experiment, an array of four Imaging Atmospheric Cherenkov Telescopes with high sensitivity and large field-of-view, has been used to search for emitters of very-high-energy (VHE, >100 GeV) $\gamma$-rays along the ...
Constraints on the multi-TeV particle population in the Coma galaxy cluster with HESS observations
(EDP Sciences, 2009)
Aims. Galaxy clusters are key targets in the search for ultra high energy particle accelerators. The Coma cluster represents one of the best candidates for such a search owing to its high mass, proximity, and the established ...
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 ...
First detection of VHE y-rays from SN 1006 by HESS
(EDP Sciences, 2010)
Aims. Recent theoretical predictions of the lowest very high energy (VHE) luminosity of SN 1006 are only a factor 5 below the previously published HESS upper limit, thus motivating further in-depth observations of this ...
A search for a dark matter annihilation signal toward the Canis Major overdensity with H.E.S.S.
(EDP Sciences, 2009)
A search for a dark matter (DM) annihilation signal into γ -rays toward the direction of the Canis Major (CMa)
overdensity is presented. The nature of CMa is still controversial and one scenario represents it as a dwarf ...
HESS very-high-energy gamma-ray sources without identified counterparts
(EDP sciences, 2008)
Context.The detection of gamma rays in the very-high-energy (VHE) energy range (100 GeV–100 TeV) provides a direct view of the parent population of ultra-relativistic particles found in astrophysical sources. For this ...
Radio imaging of the very-high-energy y-ray emission region in the central engine of a radio galaxy
(Science AAAS, 2009)
The accretion of matter onto a massive black hole is believed to feed the relativistic plasma jets
found in many active galactic nuclei (AGN). Although some AGN accelerate particles to energies
exceeding 1012 electron ...
Simultaneous HESS and Chandra observations of Sagitarius A* during an X-ray flare
(EDP Sciences, 2008)
The rapidly varying (~10 min timescale) non-thermal X-ray emission observed from Sgr A implies that particle acceleration is occuring close to the event horizon of the supermassive black hole. The TeV γ-ray source ...
Simultaneous multiwavelength observations of the second exceptional y-ray flare of PKS 2155-304 in July 2006
(EDP Sciences, 2009)
Aims. The X-ray-TeV connection and the evolution of the emitting particle population is studied in high-energy peaked BL Lac objects, by obtaining spectral information in both bands on sub-hour timescales.
Methods. ...