Variations of the TeV energy spectrum at different flux levels of Mkn 421 observed with the HEGRA system of Cherenkov telescopes

  title={Variations of the TeV energy spectrum at different flux levels of Mkn 421 observed with the HEGRA system of Cherenkov telescopes},
  author={Felix A. Aharonian and A. G. Akhperjanian and Matthias Beilicke and Konrad Bernl{\"o}hr and H. G. B{\"o}rst and H. Bojahr and O. Bolz and T. Coarasa and Jos{\'e} Luis Contreras and J Lombard́ıa Corti{\~n}a and Luigi Costamante and S. Denninghoff and Victoria Fonseca and Melaku Girma and N. G{\"o}tting and G{\"o}tz Heinzelmann and German Hermann and Andreas Heusler and W. Hofmann and Dieter Horns and Ines Jung and R. Kankanyan and M. Kestel and J. S. Kettler and Antje Kohnle and Alexander K. Konopelko and H. Kornmeyer and Daniel Kranich and Henric S. Krawczynski and H. Lampeitl and Matthias Lopez and Elke Lorenz and Francesca Lucarelli and Oscar Mang and H. Meyer and Rafayel Mirzoyan and Margherita Milite and Abelardo Moralejo and Egil Ona and M. Panter and A. Plyasheshnikov and Gerd. Puehlhofer and G. Rauterberg and Reinabelle Reyes and Wolfgang Rhode and Joachim Ripken and Geoffrey Rowell and Vatche Sahakian and M. Samorski and Martin Schilling and Melanie Siems and D. Sobzynska and Walter Stamm and Martin Tluczykont and Heinrich J. V{\"o}lk and C. A. Wiedner and Wolfgang Wittek and Ronald A. Remillard},
The nearby BL Lacertae (BL Lac) object Markarian 421 (Mkn 421) at a red shift z = 0.031 was observed to undergo strong TeV γ-ray outbursts in the observational periods from December 1999 until May 2001. The time averaged flux level F (E > 1TeV) in the 1999/2000 season was (1.43± 0.04) ·10−11 ph cm−2 s−1, whereas in the 2000/2001 season the average integral flux increased to (4.19±0.04) ·10−11 ph cm−2 s−1. Both energy spectra are curved and well fit by a power law with an exponential cut-off… CONTINUE READING
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Publications referenced by this paper.
Showing 1-2 of 2 references

Proc. of the 27th ICRC

  • M Jordan
  • Proc. of the 27th ICRC
  • 2001


  • F Piron
  • Nature
  • 1992

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