Now showing items 1-10 of 14

    • Broad-band reflection spectroscopy of MAXI J1535-571 using AstroSat: estimation of black hole mass and spin 

      Sridhar, Navin; Chandra, Sunil; Bhattacharyya, Sudip; Antia, H.M. (Oxford Univ Press, 2019)
      We report the results from AstroSat observations of the transient Galactic black hole X-ray binary MAXI J1535–571 during its hard-intermediate state of the 2017 outburst. We systematically study the individual and joint ...
    • Constraining relativistic bow shock properties in rotation-powered millisecond pulsar binaries 

      Wadiasingh, Zorawar; Venter, Christo; Böttcher, Markus; Harding, Alice K.; Baring, Matthew G. (AAS, 2017)
      Multiwavelength follow-up of unidentified Fermi sources has vastly expanded the number of known galactic-field "black widow" and "redback" millisecond pulsar binaries. Focusing on their rotation-powered state, we interpret ...
    • Constraints on particle acceleration in SS433/W50 from MAGIC and H.E.S.S. observations 

      Ahnen, M.L.; Munar-Adrover, P.; Abdalla, H.; Barnard, M.; Böttcher, M.; Davids, I.D.; Garrigoux, T.; Ivascenko, A.; Krüger, P.P.; Pekeur, N.W.; Richter, S.; Van der Walt, D.J.; Van Rensburg, C.; Venter, C.; Wadiasingh, Z.; Seyffert, A.S.; Spanier, F.; Sushch, I.; H.E.S.S. Collaboration (EDP Sciences, 2018)
      Context. The large jet kinetic power and non-thermal processes occurring in the microquasar SS 433 make this source a good candidate for a very high-energy (VHE) gamma-ray emitter. Gamma-ray fluxes above the sensitivity ...
    • Discovery of variable VHE γ-ray emission from the binary system 1FGL J1018.6-5856 

      Abramowski, A.; Böttcher, M.; Davids, I.D.; Ivascenko, A.; Krüger, P.P.; Pekeur, N.W.; Seyffert, A.S.; Spanier, F.; Sushch, I.; Van der Walt, D.J.; Venter, C.; H.E.S.S. Collaboration (EDP Sciences, 2015)
      Re-observations with the HESS telescope array of the very high-energy (VHE) source HESS J1018–589 A that is coincident with the Fermi-LAT γ-ray binary 1FGL J1018.6–5856 have resulted in a source detection significance of ...
    • Extensive broadband X-ray monitoring during the formation of a giant radio jet base in Cyg X-3 with AstroSat 

      Pahari, Mayukh; Chandra, Sunil; Yadav, J.S.; Chauhan, Jai Verdhan; Rawat, Divya (IOP Publishing, 2018)
      We present X-ray spectral and timing behavior of Cyg X-3 as observed by AstroSat during the onset of a giant radio flare on 2017 April 1–2. Within a timescale of a few hours, the source shows a transition from the hypersoft ...
    • Fermi/LAT obeservations of LS 5039 

      Abdo, A.A.; Venter, C.; Ackermann, M.; Ajello, M.; Atwood, W.B.; Fermi LAT (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 ...
    • 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.) ...
    • HESS observations of the Carina nebula and its enigmatic colliding wind binary Eta Carinae 

      Abramowski, A.; Büsching, I.; Casanova, S.; Pekeur, N.W.; Sheidaei, F.; Venter, C.; Vorster, M.; H.E.S.S. Collaboration (Oxford Univ Press, 2012)
      The massive binary system Eta Carinae and the surrounding HII complex, the Carina nebula, are potential particle acceleration sites from which very high energy (VHE; E ≥ 100 GeV) γ -ray emission could be expected. This ...
    • HESS upper limits on very high energy gamma-ray emission from the microquasar GRS 1915+105 

      Acero, F.; Büsching, I.; Davids, I.D.; Holleran, M.; De Jager, O.C.; Raubenheimer, B.C.; Venter, C.; H.E.S.S. Collaboration (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 ...
    • MSP binaries as astrophysical laboratories 

      Wadiasingh, Zorawar; Venter, Christo; Böttcher, Markus; Harding, Alice K.; Baring, Matthew G. (Cambridge Univ Press, 2018)
      Follow-up of unidentified Fermi sources has expanded the number of known galactic-field “black widow” and “redback” millisecond pulsar binaries from four to nearly 30. Several systems observed by Chandra, XMM-Newton, Suzaku, ...