Now showing items 14889-14908 of 33415

    • H-selfadjoint roots of H-selfadjoint matrices and H-polar decompositions over the quaternions 

      Van Straaten, M. (North-West University (South Africa), 2022)
      All vector spaces in this thesis will be endowed with an indefinite inner product defined by an invertible Hermitian matrix H. We study cases where the H has either complex or quaternion entries depending on the context. We ...
    • The H-test probability distribution revisited: Improved sensitivity 

      Busching, Ingo; De Jager, Ocker Cornelis (EDP Sciences, 2010)
    • H. Pieter Van der Westhuizen op 90 : 'n Biografiese oorsig 

      Meyer, Jaco (Die Suider-Afrikaanse Kerkorrelistevereniging, 2021)
      Hercules Pieter van der Westhuizen (*1931) is a South African composer who served on the Interchurch Review Commission of the Afrikaans Psalm Anthology in 1977. His contributions to the church and choir repertoire in ...
    • H. Rider Haggard : a critical study of his prose fiction 

      Terblanche, Johan David Villiers (North-West University (South Africa), 19??)
      "No abstract"
    • H.E.S.S. and Fermi-LAT observations of PSR B1259-63/LS 2883 during its 2014 and 2017 periastron passages 

      Abdalla, H.; Arcara, C.; Backes, M.; Barnard, M.; Böttcher, M.; Chand, T.; Chandra, S.; Kreter, M.; Ndiyavala, H.; Schutte, H.; Seyffert, A.S.; Van der Walt, D.J.; Van Rensburg, C.; Venter, C.; Wadiasingh, Z.; Zacharias, M.; Żywucka, N.; Fermi LAT; H.E.S.S. Collaboration (EDP Sciences, 2020)
      Context. PSR B1259–63/LS 2883 is a gamma-ray binary system consisting of a pulsar in an eccentric orbit around a bright Oe stellar-type companion star that features a dense circumstellar disc. The bright broad-band emission ...
    • H.E.S.S. and Suzaku observations of the Vela X pulsar wind nebula 

      Abdalla, H.; Arcaro, C.; Backes, M.; Barnard, M.; Böttcher, M.; Chand, T.; Chandra, S.; Ndiyavala, H.; Schutte, H.; Seyffert, A.S.; Van der Walt, D.J.; Van Rensburg, C.; Venter, C.; Wadiasingh, Z.; Zacharias, M.; Zywucka, N.; H.E.S.S. Collaboration (EDP Sciences, 2019)
      Context. Pulsar wind nebulae (PWNe) represent the most prominent population of Galactic very-high-energy gamma-ray sources and are thought to be an efficient source of leptonic cosmic rays. Vela X is a nearby middle-aged ...
    • H.E.S.S. constraints on dark matter annihilations towards the Sculptor and Carina dwarf galaxies 

      Abramowski, A.; Büsching, I.; De Jager, O.C.; Venter, C.; Vorster, M.; H.E.S.S. Collaboration (Elsevier, 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. detection of TeV emission from the interaction region between the supernova remnant G349.7+0.2 and a molecular cloud 

      Abramowski, A.; Böttcher, M.; Davids, I.D.; Ivascenko, A.; Krüger, P.P.; Pekeur, N.W.; Spanier, F.; Sushch, I.; Venter, C.; Vorster, M.; H.E.S.S. Collaboration (EDP Sciences, 2015)
      G349.7+0.2 is a young Galactic supernova remnant (SNR) located at the distance of 11.5 kpc and observed across the entire electromagnetic spectrum from radio to high energy (HE; 0.1 GeV <E< 100 GeV) γ-rays. Radio and ...
    • H.E.S.S. detection of very high-energy γ-ray emission from the quasar PKS 0736+017 

      Abdalla, H.; Arcaro, C.; Backes, M.; Barnard, M.; Böttcher, M.; Chand, T.; Chandra, S.; Ndiyavala, H.; Schutte, H.; Seyffert, A.S.; Van der Walt, D.J.; Van Rensburg, C.; Venter, C.; Wadiazingh, Z.; Zacharias, M.; Zywucka, N.; H.E.S.S. Collaboration (EDP Sciences, 2020)
      Context. Flat-spectrum radio-quasars (FSRQs) are rarely detected at very high energies (E ≥ 100 GeV) due to their low-frequency-peaked spectral energy distributions. At present, only six FSRQs are known to emit very ...
    • H.E.S.S. discovery of very high energy γ-ray emission from PKS 0625−354 

      Abdalla, H.; Barnard, M.; Davids, I.D.; Garrigoux, T.; Ivascenko, A.; Pekeur, N.W.; Seyffert, A.S.; Spanier, F.; Sushch, I.; Van der Walt, D.J.; Van Rensburg, C.; Venter, C.; Wadiasingh, Z.; H.E.S.S. Collaboration (Oxford Univ Press, 2018)
      PKS 0625−354 (z = 0.055) was observed with the four High Energy Stereoscopic System (H.E.S.S.) telescopes in 2012 during 5.5 h. The source was detected above an energy threshold of 200 GeV at a significance level of 6.1σ. ...
    • H.E.S.S. discovery of very-high-energy gamma-ray emission of PKS 1440-389 

      Prokoph, H.; Böttcher, M.; Sushch, I.; Becherinia, Y.; Boisson, C. (Sissa Medialab, 2015)
      Blazars are the most abundant class of known extragalactic very-high-energy (VHE, E>100 GeV) gamma-ray sources. However, one of the biggest difficulties in investigating their VHE emission resides in their limited number, ...
    • H.E.S.S. discovery of VHE y-rays from the quasar PKS 1510-089 

      Abramowski, A.; Casanova, S.; Krüger, P.P.; Pekeur, N.W.; Sheidaei, F.; Venter, C.; Vorster, M.; H.E.S.S. Collaboration (EDP Sciences, 2013)
      The quasar PKS 1510-089 (z = 0.361) was observed with the H.E.S.S. array of imaging atmospheric Cherenkov telescopes during high states in the optical and GeV bands, to search for very high energy (VHE, defined as E ≥ 0.1 ...
    • The H.E.S.S. Galactic plane survey 

      Abdalla, H.; Barnard, M.; Böttcher, M.; Garrigoux, T.; Ivascenko, A.; Krüger, P.P.; Pekeur, N.W.; Seyffert, A.S.; Spanier, F.; Sushch, I.; Van der Walt, D.J.; Van Rensburg, C.; Venter, C.; Wadiasingh, Z.; Zacharias, M.; H.E.S.S. Collaboration (EDP Sciences, 2018)
      We present the results of the most comprehensive survey of the Galactic plane in very high-energy (VHE) γ-rays, including a public release of Galactic sky maps, a catalog of VHE sources, and the discovery of 16 new sources ...
    • The H.E.S.S. II GRB observation scheme 

      Parsons, R.D.; Garrigoux, T.; Schüssler, F.; Balzer, A.; Füssling, M. (AIP, 2017)
      Gamma-ray bursts (GRBs) are some of the Universe’s most enigmatic and exotic events. However, at energies above 10 GeV their behaviour remains largely unknown. Although space based telescopes such as the Fermi-LAT have ...
    • H.E.S.S. limits on linelike dark matter signatures in the 100 GeV to 2 TeV energy range close to the galactic center 

      Abdallah, H.; Barnard, M.; Böttcher, M.; Davids, I.D.; Garrigoux, T.; Ivascenko, A.; Krüger, P.P.; Pekeur, N.W.; Seyffert, A.S.; Spanier, F.; Sushch, I.; Van der Walt, D.J.; Venter, C.; Wadiasingh, Z.; H.E.S.S. Collaboration (APS, 2016)
      A search for dark matter line-like signals was performed in the vicinity of the Galactic Centre by the H.E.S.S. experiment on observational data taken in 2014. An unbinned likelihood analysis was developed to improve the ...
    • H.E.S.S. monitoring of PKS 2155-304 in 2015 and 2016 

      Wierzcholska, Alicja; Zacharias, Michael; Jankowsky, Felix; Wagner, Stefan (MDPI, 2019)
      PKS 2155-304 is one of the brightest blazar located in Southern Hemisphere, monitored with H.E.S.S. since the first light of the experiment. Here we report multiwavelength monitoring observations collected during the ...
    • H.E.S.S. observations of RX J1713.7−3946 with improved angular and spectral resolution: evidence for gamma-ray emission extending beyond the X-ray emitting shell 

      Abdalla, H.; Barnard, M.; Böttcher, M.; Davids, I.D.; Garrigoux, T.; Ivascenko, A.; Krüger, P.P.; Pekeur, N.W.; Seyffert, A.S.; Spanier, F.; Sushch, I.; Van der Walt, D.J.; Van Rensburg, C.; Venter, C.; Wadiasingh, Z.; H.E.S.S. Collaboration (EDP Sciences, 2018)
      Supernova remnants exhibit shock fronts (shells) that can accelerate charged particles up to very high energies. In the past decade, measurements of a handful of shell-type supernova remnants in very high-energy gamma ...
    • H.E.S.S. observations of the binary system PSR B1259-63/LS 2883 around the 2010/2011 periastron passage 

      Abramowski, A.; Casanova, S.; Krüger, P.P.; Pekeur, N.W.; Sheidaei, F.; Venter, C.; Vorster, M.; H.E.S.S. Collaboration (EDP Sciences, 2013)
      Aims. We present very high energy (VHE; E > 100 GeV) data from the γ-ray binary system PSR B1259-63/LS 2883 taken around its periastron passage on 15th of December 2010 with the High Energy Stereoscopic System (H.E.S.S.) ...
    • H.E.S.S. observations of the Crab during its March 2013 GeV gamma-ray flare 

      Abramowski, A.; Böttcher, M.; Casanova, S.; Davids, I.D.; Krüger, P.P.; Pekeur, N.W.; Sushch, I.; Venter, C.; Vorster, M.; H.E.S.S. Collaboration (EDP Sciences, 2014)
      Context. On March 4, 2013 the Fermi-LAT and AGILE reported a flare from the direction of the Crab nebula in which the high-energy (HE; E > 100 MeV) flux was six times above its quiescent level. Simultaneous observations ...
    • H.E.S.S. observations of the flaring gravitationally lensed galaxy PKS 1830-211 

      Abdalla, H.; Arcaro, C.; Backes, M.; Barnard, M.; Böttcher, M.; Chand, T.; Chandra, S.; Ndiyavala, H.; Schutte, H.; Seyffert, A.S.; Van der Walt, D.J.; Van Rensburg, C.; Venter, C.; Wadiasingh, Z.; Zacharias, M.; H.E.S.S. Collaboration (Oxford Univ Press, 2019)
      PKS 1830–211 is a known macrolensed quasar located at a redshift of z = 2.5. Its high-energy gamma-ray emission has been detected with the Fermi-Large Area Telescope (LAT) instrument and evidence for lensing was obtained ...