TeVγ-ray light curve and energy spectrum of Mkn 421 during its 2001 flare as measured with HEGRA CT1

Autor: Henric Krawczynski, M. A. Lopez, J. Ripken, M. Beilicke, H. Lampeitl, I. Sevilla, M. Kestel, M. Panter, David Paneque, E. Lorenz, Dieter Horns, W. Wittek, Robert Wagner, H. J. Meyer, M. Schilling, D. Kranich, Florian Goebel, M. Samorski, H. Bojahr, G. Hermann, Abelardo Moralejo, N. Tonello, Werner Hofmann, I. Jung, G. Heinzelmann, M. Tluczykont, Dorota Sobczyńska, Konrad Bernlöhr, Wolfgang Rhode, N. Götting, A. Plyasheshnikov, J. A. Coarasa, R. Kankanyan, A. Konopelko, A. Heusler, Jose Luis Contreras, Juan Cortina, H. Börst, C. A. Wiedner, A. Kohnle, M. Siems, T. Schweizer, O. Mang, Felix Aharonian, M. Girma, S. Denninghoff, E. Ona-Wilhelmi, Gerd Pühlhofer, W. Stamm, V. Fonseca, V. Sahakian, F. Lucarelli, Gavin Rowell, R. de los Reyes, R. Mirzoyan, J. Kettler, Heinrich J. Völk, A. G. Akhperjanian, O. Bolz, V. Vitale
Rok vydání: 2003
Předmět:
Zdroj: Astronomy & Astrophysics. 410:813-821
ISSN: 1432-0746
0004-6361
Popis: In the first months of 2001 the AGN Mkn 421 showed highly variable, strong TeV activity at flux levels frequently exceeding 1 Crab. Here we present the light curve and energy spectrum of Mkn 421 as measured with the HEGRA stand alone telescope CT1. Around 30% of the data were taken under moonlight conditions. The spectrum shows a significant exponential energy cuto at around 3.4 TeV. The results from the dark night- and the moon data are in excellent agreement with each other. A significant spectral shape variation depending on the flux level has been found. The TeV light curve is also found to be highly correlated with the X-ray light curve of the RXTE/ ASM satellite, showing no significant time lag larger than 0.2 d. The derived correlation coecient of 0.83 corresponds to a 5:2 significance.
Databáze: OpenAIRE