Now showing items 1-20 of 23

    • The 2010 very high energy γ-ray flare and 10 years of multi-wavelength observations of M 87 

      Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Büsching, Ingo; De Jager, Ocker Cornelis; Sheidaei, F.; Vorster, M. (IOP publishing, 2012)
      The giant radio galaxy M 87 with its proximity (16 Mpc), famous jet, and very massive black hole ((3 – 6) × 109 M☉) provides a unique opportunity to investigate the origin of very high energy (VHE; E > 100 GeV) γ-ray ...
    • Constraints on the gamma-ray emission from the cluster-scale AGN outburst in the hydra A galaxy cluster 

      Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Casanova, S.; Pekeur, Nicolette Whilna; Sheidaei, F.; Venter, Christo; Vorster, Michael Johannes; Büsching, Ingo (EDP Sciences, 2012)
      Context. In some galaxy clusters, powerful active galactic nuclei (AGN) have blown bubbles with cluster scale extent into the ambient medium. The main pressure support of these bubbles is not known to date, but cosmic rays ...
    • Detection of very-high-energy y-ray emission from the vicinity of PSR B1706-44 and G 343.1-2.3 with H.E.S.S.  

      Davids, Isak Delberth; Holleran, Mathew; Venter, Christo; Büsching, Ingo; De Jager, Ocker Cornelis (EDP Sciences, 2011)
      The γ-ray pulsar PSRB1706−44 and the adjacent supernova remnant (SNR) candidate G343.1−2.3 were observed by H.E.S.S. during a dedicated observation campaign in 2007. As a result of this observation campaign, a new source ...
    • Discovery of extended VHE Y-ray emission from the vicinity of the young massive stellar cluster Westerlund 1 

      Abramowski, A.; Büsching, Ingo; De Jager, Ocker Cornelis; Sheidaei, F.; Venter, Christo; Vorster, M. (EDP Science, 2012)
      Aims. Results obtained in very-high-energy (VHE; E≥100GeV) γ-ray observations performed with the H.E.S.S. telescope array are used to investigate particle acceleration processes in the vicinity of the young massive stellar ...
    • Discovery of hard-spectrum y-ray emission from the BL Lacertae object 1ES0414+009 

      Abramowski, A.; Büsching, Ingo; De Jager, Ocker Cornelis; Sheidaei, F.; Venter, Christo; Vorster, Michael Johannes (EDP Science, 2012)
      Context. 1ES 0414 + 009 (z = 0.287) is a distant high-frequency-peaked BL Lac object, and has long been considered a likely emitter of very-high-energy (VHE, E > 100 GeV) γ-rays due to its high X-ray and radio flux. Aims. ...
    • Discovery of the source HESS J1356-645 associated with the young and energetic PSR J1357-6429 

      Venter, Christo; Vorster, Michael Johannes; Büsching, Ingo; De Jager, Ocker Cornelis (EDP Sciences, 2011)
      Context. Several newly discovered very-high-energy (VHE; E > 100 GeV) γ-ray sources in the Galaxy are thought to be associated with energetic pulsars. Among them, middle-aged (≳104 yr) systems exhibit large centre-filled ...
    • Discovery of VHE emission towards the carina arm region with the H.E.S.S. telescope array: HESS J1018-589 

      Abramowski, A.; Büsching, Ingo; Casanova, S.; De Jager, Ocker Cornelis; Pekeur, Nicolette Whilna; Sheidaei, F.; Venter, Christo; Vorster, Michael Johannes (EDP Science, 2012)
      The Carina arm region, containing the supernova remnant SNR G284.3–1.8, the high-energy (HE; E > 100 MeV) binary 1FGL J1018.6–5856 and the energetic pulsar PSR J1016–5857 and its nebula, has been observed with the H.E.S.S. ...
    • H.E.S.S. constraints on dark matter annihilations towards the sculptor and carina dwarf galaxies 

      Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A.G.; Anton, G.; Barnacka, A.; Barres de Almeida, U.; Bazer-Bachi, A.R.; Becherini, Y.; Becker, J.; Behera, B.; Bernlöhr, K.; Bochow, A.; Boisson, C.; Bolmont, J.; Bordas, P.; Borrel, V.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Büsching, Ingo; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P.M.; Charbonnier, A.; Chaves, R.C.G.; Cheesebrough, A.; Chounet, L. M.; Clapson, A.C.; Coignet, G.; Conrad, J.; Dalton, M.; Daniel, M.K.; De Jager, Ocker Cornelis; De Los Reyes, R.; De Naurois, M.; De Oña Wilhelmi, E.; Degrange, B.; Deil, C.; Dickinson, H.J.; Djannati-Ataï, A.; Domainko, W.; Drury, L.O'C.; Dubois, F.; Dubus, G.; Dyks, J.; Dyrda, M.; Egberts, K.; Eger, P.; Espigat, P.; Fallon, L.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M.V.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gallant, Y.A.; Gast, H.; Gérard, L.; Gerbig, D.; Giebels, B.; Glicenstein, J.F.; Glück, B.; Goret, P.; Göring, D.; Hague, J.D.; Hampf, D.; Hauser, M.; Heinz, S.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J. A.; Hoffmann, A.; Hofmann, W.; Hofverberg, P.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Keogh, D.; Kerschhaggl, M.; Khangulyan, D.; Khélifi, B.; Klochkov, D.; Kluzniak, W.; Kneiske, T.; Komin, Nu; Kosack, K.; Kossakowski, R.; Laffon, H.; Lamanna, G.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.C.; Marandon, V.; Marcowith, A.; Masbou, J.; Maurin, D.; Maxted, N.; Mccomb, T.J L.; Medina, M.C.; Méhault, J.; Moderski, R.; Moulin, E.; Naumann, C.L.; Naumann-Godo, M.; Nedbal, D.; Nekrassov, D.; Nguyen, N.; Nicholas, B.; Niemiec, J.; Nolan, S.J.; Ohm, S.; Olive, J.F.; Opitz, B.; Ostrowski, M.; Panter, M.; Paz Arribas, M.; Pedaletti, G.; Pelletier, G.; Petrucci, P.O.; Pita, S.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raue, M.; Rayner, S.M.; Reimer, A.; Reimer, O.; Renaud, M.; Rieger, F.; Ripken, J.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C.B.; Ruppel, J.; Ryde, F.; Sahakian, V.; Santangelo, A.; Schlickeiser, R.; Schöck, F.M.; Schönwald, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Shalchi, A.; Sikora, M.; Skilton, J.L.; Sol, H.; Spengler, G.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Sushch, I.; Szostek, A.; Tavernet, J.P.; Terrier, R.; Tibolla, O.; Tluczykont, M.; Valerius, K.; Van Eldik, C.; Vasileiadis, G.; Venter, Christo; Vialle, J.P.; Viana, A.; Vincent, P.; Vivier, M.; Völk, H J.; Volpe, F.; Vorobiov, S.; Vorster, Michael Johannes; Wagner, S.J.; Ward, M. (Elsevier Science, 2011)
      The Sculptor and Carina dwarf spheroidal galaxies were observed with the H.E.S.S. Cherenkov telescope array between January 2008 and December 2009. The data sets consist of a total of 11.8 h and 14.8 h of high quality data, ...
    • H.E.S.S. observations of the globular clusters NGC 6388 and M15 and search for a dark matter signal 

      Venter, Christo; Vorster, Michael Johannes; Büsching, Ingo; De Jager, Ocker Cornelis (IOP Publishing, 2011)
      Observations of the globular clusters (GCs) NGC 6388 and M15 were carried out by the High Energy Stereoscopic System array of Cherenkov telescopes for a live time of 27.2 and 15.2 hr, respectively. No gamma-ray signal is ...
    • HESS J1943+213: a candidate extreme BL Lacertae object 

      Venter, Christo; Vorster, Michael Johannes; Büsching, Ingo; De Jager, Ocker Cornelis (EDP Sciences, 2011)
      We report on a newly detected point-like source, HESS J1943+213 located in the Galactic plane. This source coincides with an unidentified hard X-ray source IGR J19443+2117, which was proposed to have radio and infrared ...
    • Identification of HESS J1303-631 as a pulsar wind nebula through y-ray, x-ray, and radio observations 

      Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Anton, G.; Balzer, A.; Casanova, S.; Pekeur, Nicolette Whilna; Sheidaei, F.; Venter, Christo; Vorster, Michael Johannes; Büsching, Ingo (EDP Science, 2012)
      Aims. The previously unidentified very high-energy (VHE; E > 100 GeV) γ-ray source HESS J1303−631, discovered in 2004, is re-examined including new data from the H.E.S.S. Cherenkov telescope array in order to identify this ...
    • Modeling the modulation of galactic and jovian electrons by stochastic processes 

      Kopp, Andreas; Potgieter, Marthinus Steenkamp; Strauss, Roelf Du Toit; Büsching, Ingo (IOP Publishing, 2011)
      We present a newly developed numerical modulation model to study the transport of galactic and Jovian electrons in the heliosphere. The model employs stochastic differential equations (SDEs) to solve the corresponding ...
    • Modelling heliospheric current sheet drift in stochastic cosmic ray transport models 

      Kopp, Andreas; Potgieter, Marthinus Steenkamp; Strauss, Roelf du Toit; Büsching, Ingo (Springer, 2012)
      Drifts are one of the major cosmic ray modulation mechanisms in the heliosphere. Three types of drifts occur in the background heliospheric magnetic field, namely curvature, gradient and current sheet drifts. The last ...
    • A multiwavelength view of the flaring state of PKS 2155-304 in 2006 

      Abramowski, A.; Büsching, Ingo; De Jager, Ocker Cornelis; Venter, C.; Vorster, M. (EDP Sciences, 2012)
      Context: Multiwavelength (MWL) observations of the blazar PKS 2155-304 during two weeks in July and August 2006, the period when two exceptional flares at very high energies (VHE, E ≳ 100 GeV) occurred, provide a detailed ...
    • A new SNR with TeV shell-type morphology: HESS J1731-347 

      Venter, Christo; Vorster, Michael Johannes; Büsching, Ingo; De Jager, Ocker Cornelis (EDP Sciences, 2011)
      Aims. The recent discovery of the radio shell-type supernova remnant (SNR), G353.6-0.7, in spatial coincidence with the unidentified TeV source HESS J1731−347 has motivated further observations of the source with the High ...
    • On the propagation times and energy losses of cosmic rays in the heliosphere 

      Kopp, Andreas; Potgieter, Marthinus Steenkamp; Strauss, Roelf du Toit; Büsching, Ingo (American Geophysical Union, 2011)
      We present calculations of the propagation times and energy losses of cosmic rays as they are transported through the heliosphere. By calculating these quantities for a spatially 1D scenario, we benchmark our numerical ...
    • Primary particle acceleration above 100 TeV in the shell-type supernova remnant RX J1713.7-3946 with deep H.E.S.S. observations (Corrigendum) 

      Holleran, Mathew; Raubenheimer, Barend Christoffel; Venter, Christo; Büsching, Ingo; De Jager, Ocker Cornelis (EDP Sciences, 2011)
      Primary particle acceleration above 100 TeV in the shell-type supernova remnant RX J1713.7-3946 with deep H.E.S.S. observations (Corrigendum)
    • Revisiting the Westerlund 2 field with the HESS telescope array 

      Abramowski, A.; Acero, F.; Aharonian, F.; Anton, G.; Barnacka, A.; Becherini, Y.; Becker, J.; Behera, B.; Bernlöhr, K.; Bochow, A.; Boisson, C.; Bolmont, J.; Bordas, P.; Borrel, V.; Boutelier, T.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Casanova, S.; Cerruti, M.; Charbonnier, A.; Cheesebrough, A.; Coignet, G.; Conrad, J.; Dalton, M.; Davids, Isak Delberth; Dawson, J.; De, Jager Ocker Cornelis; De, Los Reyes; De, Naurois; De, Oña Wilhelmi; Degrange, B.; Deil, C.; Domainko, W.; Dubois, F.; Dubus, G.; Dyks, J.; Dyrda, M.; Egberts, K.; Eger, P.; Espigat, P.; Fallon, L.; Farnier, C.; Fegan, S.; Feinstein, F.; Fiasson, A.; Fontaine, G.; Förster, A.; Fukui, Y.; Furukawa, N.; Gabici, S.; Gallant, Y. A.; Gérard, L.; Gerbig, D.; Giebels, B.; Glicenstein, J. F.; Glück, B.; Goret, P.; Göring, D.; Hague, J. D.; Hampf, D.; Hauser, M.; Heinz, S.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J. A.; Hoffmann, A.; Hofmann, W.; Hofverberg, P.; Holleran, Mathew; Hoppe, S.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jung, I.; Katarzynski, K.; Katz, U.; Kaufmann, S.; Kawamura, A.; Keogh, D.; Kerschhaggl, M.; Khangulyan, D.; Khélifi, B.; Klochkov, D.; Kluzniak, W.; Kneiske, T.; Komin, N. U.; Kosack, K.; Kossakowski, R.; Lamanna, G.; Lenain, J. P.; Lennarz, D.; Lohse, T.; Lu, C. C.; Marandon, V.; Marcowith, A.; Masbou, J.; Maurin, D.; Mccomb, T. J. L.; Medina, M. C.; Méhault, J.; Moderski, R.; Moulin, E.; Naumann-godo, M.; Nedbal, D.; Nekrassov, D.; Nguyen, N.; Nicholas, B.; Niemiec, J.; Nolan, S. J.; Ohama, A.; Ohm, S.; Olive, J. F.; Opitz, B.; Orford, K. J.; Ostrowski, M.; Panter, M.; Paz, Arribas; Pedaletti, G.; Pelletier, G.; Petrucci, P. O.; Pita, S.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raue, M.; Rayner, S. M.; Reimer, A.; Reimer, O.; Renaud, M.; Rieger, F.; Ripken, J.; Rob, L.; Rosier-lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Ruppel, J.; Ryde, F.; Sahakian, V.; Sano, H.; Santangelo, A.; Schlickeiser, R.; Schöck, F. M.; Schönwald, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Shalchi, A.; Sikora, M.; Skilton, J. L.; Sol, H.; Spengler, G.; Stawarz, L.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Sushch, I.; Szostek, A.; Tam, P. H.; Tavernet, J. P.; Terrier, R.; Tibolla, O.; Tluczykont, M.; Valerius, K.; Van Eldik, C.; Vasileiadis, G.; Venter, Christo; Vialle, J. P.; Viana, A.; Vincent, P.; Vivier, M.; Völk, H. J.; Akhperjanian, A.G.; Barres de Almeida, U.; Bazer-Bachi, A.R.; Büsching, Ingo; Chadwick, P.M.; Chaves, R.C.G.; Chounet, L.M.; Clapson, A.C.; Daniel, M.K.; Dickinson, H.J.; Djannati-Ataï, A.; Drury, L.O'C; Fernandes, M.V.; Füßling, M.; HESS Collaboration (EDP Sciences, 2011)
      Aims. Previous observations with the HESS telescope array revealed the existence of extended very-high-energy (VHE; E > 100 GeV) γ-ray emission, HESS J1023–575, coincident with the young stellar cluster Westerlund 2. At ...
    • Search for dark matter annihilation signals from the fornax galaxy cluster with HESS 

      Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Venter, Christo; Vorster, Michael Johannes; Büsching, Ingo; De Jager, Ocker Cornelis (IOP publishers, 2012)
      The Fornax galaxy cluster was observed with the High Energy Stereoscopic System for a total live time of 14.5 hr, searching for very high energy (VHE; E > 100GeV) γ -rays from dark matter (DM) annihilation. No significant ...
    • Search for Lorentz invariance breaking with a likelihood fit of the PKS 2155-304 flare data taken on MJD 53944 

      Venter, Christo; Vorster, Michael Johannes; Büsching, Ingo; De Jager, Ocker Cornelis (Elsevier Science, 2011)
      Several models of Quantum Gravity predict Lorentz Symmetry breaking at energy scales approaching the Planck scale (∼1019 GeV). With present photon data from the observations of distant astrophysical sources, it is possible ...