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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 ...
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 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. ...
HESS upper limit on the very high energy γ-ray emission from the globular cluster 47 Tucanae
(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 ...
Probing the ATIC peak in the cosmic-ray electron spectrum with H.E.S.S.
(EDP Sciences, 2009)
The measurement of an excess in the cosmic-ray electron spectrum between 300 and 800 GeV by the ATIC experiment has – together with
the PAMELA detection of a rise in the positron fraction up to
≈
100 GeV – ...
Simultaneous observations of PKS 2155-304 with HESS, FERMI, RXTE, and ATOM: spectral energy distributions and variability in a low state
(IOP Publishing, 2009)
We report on the first simultaneous observations that cover the optical, X-ray, and high-energy gamma-ray bands of the BL Lac object PKS 2155–304. The gamma-ray bands were observed for 11 days, between 2008 August 25 and ...
HESS upper limits on very high energy gamma-ray emission from the microquasar GRS 1915+105
(EDP Sciences, 2009)
Context. High energy particles reside in the relativistic jets of microquasars, making them possible sources of very high energy radiation (VHE, >100 GeV). Detecting this emission would provide a new handle on jet ...
Very high energy γ-ray observations of the binary PSR B1259-63/SS2883 around the 2007 Periastron
(EDP Sciences, 2009)
Aims. This article presents very-high-energy (VHE; E > 100 GeV) data from the γ-ray binary PSR B1259-63 as taken during the years 2005, 2006 and before as well as shortly after the 2007 periastron passage. These data extend ...