Now showing items 1-9 of 9

    • Chandra and HESS observations of the supernova remnant CTB 37B 

      Aharonian, F.; Büsching, I.; De Jager, O.C.; Holleran, M.; Raubenheimer, B.C.; Venter, C. (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 ...
    • Constraints on the multi-TeV particle population in the Coma galaxy cluster with HESS observations 

      Aharonian, F.; Büsching, I.; Davids, I.D.; De Jager, O.C.; Holleran, M.; Raubenheimer, B.C.; Venter, C. (EDP Sciences, 2009)
    • HESS observations and VLT spectroscopy of PG 1553+113 

      Aharonian, F.; Büshing, I.; De Jager, O.C.; Holleran, M.; Raubenheimer, B.C.; Venter, C. (EDP Sciences, 2008)
      Aims.The properties of the very high energy (VHE; GeV) γ-ray emission from the high-frequency peaked BL Lac PG 1553+113 are investigated. An attempt is made to measure the currently unknown redshift of this object. Methods.VHE ...
    • HESS observations of y-ray bursts in 2003-2007 

      Aharonian, F.; Büsching, I.; De Jager, O.C.; Holleran, M.; Raubenheimer, B.C.; Venter, C. (EDP Sciences, 2009)
      Aims. Very-high-energy (VHE; $\ga$100 GeV) $\gamma $-rays are expected from $\gamma $-ray bursts (GRBs) in some scenarios. Exploring this photon energy regime is necessary for understanding the energetics and properties ...
    • HESS upper limit on the very high energy γ-ray emission from the globular cluster 47 Tucanae 

      Aharonian, F.; Holleran, M.; Büsching, I.; Davids, I.D.; De Jager, O.C.; Raubenheimer, B.C.; Venter, C. (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 ...
    • HESS upper limits for Kepler's supernova remnant 

      B�sching, I.; De Jager, O.C.; Holleran, M.; Raubenheimer, B.C.; Venter, C. (EDP sciences, 2008)
      Aims. Observations of Kepler's supernova remnant (G4.5+6.8) with the HESS telescope array in 2004 and 2005 with a total live time of 13 h are presented. Methods. Stereoscopic imaging of Cherenkov radiation from extensive ...
    • HESS very-high-energy gamma-ray sources without identified counterparts 

      B�sching, I.; De Jager, O.C.; Holleran, M.; Raubenheimer, B.C.; Venter, C. (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 ...
    • Simultaneous HESS and Chandra observations of Sagitarius A* during an X-ray flare 

      Aharonian, F.; Büsching, I.; De Jager, O.C.; Holleran, M.; Raubenheimer, B.C.; Venter, C. (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 ...
    • Upper limits from HESS active galactic nuclei observations in 2005-2007 

      Aharonian, F.; Büsching, I.; De Jager, O.C.; Holleran, M.; Raubenheimer, B.C.; Venter, C. (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 ...