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Now showing items 1-10 of 12
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 ...
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. ...
Upper limits from HESS active galactic nuclei observations in 2005-2007
(EDP Sciences, 2008)
Aims.Very high energy (VHE; GeV) γ-ray studies were performed for 18 active galactic nuclei (AGN) from a variety of AGN classes.
Methods.VHE observations of a sample of 14 AGN, considered candidate VHE emitters, were ...
Discovery of VHE gamma-rays from the high-frequency-peaked BL Lacertae object RGB J0152+017
(EDP Sciences, 2008)
Aims. The BL Lac object RGB J0152+017 (z=0.080) was predicted to be a very high-energy (VHE; >100 GeV) $\gamma$-ray source, due to its high X-ray and radio fluxes. Our aim is to understand the radiative processes by ...
Very high energy gamma-ray observations of the galaxy clusters Abell 496 and Abell 85 with HESS
(2009)
Aims. The nearby galaxy clusters Abell 496 and Abell 85 are studied in the very high-energy (VHE, GeV) band to investigate VHE cosmic rays (CRs) in this class of objects which are the largest gravitationally bound systems ...
Chandra and HESS observations of the supernova remnant CTB 37B
(EDP Sciences, 2008)
We discovered the >100 GeV γ-ray source, HESS J1713−381, apparently associated with the shell-type supernova remnant (SNR) CTB37B, using
HESS in 2006. In 2007 we performed X-ray follow-up observations with Chandra with ...
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 observations of the prompt and afterglow phases of GRB 060602B
(IOP Publishing, 2009)
We report on the first completely simultaneous observation of a gamma-ray burst (GRB) using an array of Imaging Atmospheric Cherenkov Telescopes, which is sensitive to photons in the very high energy (VHE) γ-ray range (gsim ...
Fermi/LAT obeservations of LS 5039
(IOP Publishing, 2009)
The first results from observations of the high-mass X-ray binary LS 5039 using the Fermi Gamma-ray Space Telescope data between 2008 August and 2009 June are presented. Our results indicate variability that is consistent ...
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 ...