Browsing by Subject "Galaxies: nuclei"

Now showing items 1-3 of 3

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

      Abramowski, A.; Büsching, I.; De Jager, O.C.; Sheidaei, F.; Venter, C.; Vorster, M.; H.E.S.S. Collaboration (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 ...

    • Characterizing the γ-ray long-term variability of PKS 2155-304 with H.E.S.S. and Fermi-LAT 

      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, 2017)
      Studying the temporal variability of BL Lac objects at the highest energies provides unique insights into the extreme physical processes occurring in relativistic jets and in the vicinity of super-massive black holes. To ...

    • RoboPol: the optical polarization of gamma-ray-loud and gamma-ray-quiet blazars 

      Angelakis, E.; Böttcher, M.; Hovatta, T.; Blinov, D.; Pavlidou, V. (Oxford Univ Press, 2016)
      We present average R-band optopolarimetric data, as well as variability parameters, from the first and second RoboPol observing season. We investigate whether gamma-ray-loud and gamma-ray-quiet blazars exhibit systematic ...