Hour-Scale Multiwavelength Variability in Markarian 421

M. Catanese; I. H. Bond; S. M. Bradbury; A. C. Breslin; J. H. Buckley; A. M. Burdett; D. A. Carter-Lewis; M. F. Cawley; S. Dunlea; M. D'Vali; D. J. Fegan; S. J. Fegan; J. P. Finley; J. A. Gaidos; T. A. Hall; A. M. Hillas; D. Horan; J. Knapp; F. Krennrich; S. Le Bohec; R. W. Lessard; C. Masterson; P. Moriarty; J. Quinn; H. J. Rose; F. W. Samuelson; G. H. Sembroski; V. V. Vassiliev; T. C. Weekes; L. Maraschi; G. Fossati; F. Tavecchio; L. Chiappetti; A. Celotti; G. Ghisellini; P. Grandi; E. Pian; G. Tagliaferri; A. Treves

arXiv · astro-ph/9906209

Hour-Scale Multiwavelength Variability in Markarian 421

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Abstract

Markarian 421 was observed for about four days with BeppoSAX and the Whipple Observatory gamma-ray telescope in April 1998. A pronounced, well-defined, flare with hour-scale variability was observed simultaneously in X-rays and very high energy gamma-rays. These data provide the first evidence that the X-ray and TeV intensities are well correlated on time-scales of hours. While the rise of the flare occurred on a similar time-scale in the two wavebands, the decay of the flare was much more rapid in gamma rays, providing the first clear indication that the X-ray and gamma-ray emission may not be completely correlated in Markarian 421.

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M. Catanese, I. H. Bond, S. M. Bradbury, A. C. Breslin, J. H. Buckley, A. M. Burdett, D. A. Carter-Lewis, M. F. Cawley, S. Dunlea, M. D'Vali, D. J. Fegan, S. J. Fegan, J. P. Finley, J. A. Gaidos, T. A. Hall, A. M. Hillas, D. Horan, J. Knapp, F. Krennrich, S. Le Bohec, R. W. Lessard, C. Masterson, P. Moriarty, J. Quinn, H. J. Rose, F. W. Samuelson, G. H. Sembroski, V. V. Vassiliev, T. C. Weekes, L. Maraschi, G. Fossati, F. Tavecchio, L. Chiappetti, A. Celotti, G. Ghisellini, P. Grandi, E. Pian, G. Tagliaferri, A. Treves. 1999-06-11. Hour-Scale Multiwavelength Variability in Markarian 421. https://arxiv.org/abs/astro-ph/9906209

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