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Contributions from nearby pulsars to the local cosmic ray electron spectrum
(Elsevier, 2008)
PSR J0437-4715 is one of the closest millisecond pulsars (MSPs) to Earth, lying at a distance of _140 pc. This pulsar has a characteristic age of 4.9 Gyr and a relatively low spindown power of _1034 ergs/s. During its ...
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 ...
Detection of gamma rays from a starburst galaxy
(AAAS, 2009)
Starburst galaxies exhibit in their central regions a highly increased rate of supernovae, the remnants of which are thought to accelerate energetic cosmic rays up to energies of ~1015 electron volts. We report the detection ...
HESS upper limit on the very high energy gammay-ray emission from the globular cluster 47 Tucanae (Research Note)
(EDP sciences, 2009)
Observations of the globular cluster 47 Tucanae (NGC 104), which contains at least 23 ms pulsars, were performed with the HESS telescope
system. The observations lead to an upper limit of F(E > 800 GeV) < 6.7 × 10−13 cm−2 ...
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 ...
Predictions of gamma-ray emission from globular cluster millisecond pulsars above 100 MeV
(IOP Publishing, 2009)
The recent Fermi detection of the globular cluster (GC) 47 Tucanae highlighted the importance of modeling
collective gamma-ray emission of millisecond pulsars (MSPs) in GCs. Steady flux from such populations is also
expected ...
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. ...