Abstract We present five EXOSAT observations of the Seyfert galaxy NGC6814. The source is found to be variable at both soft (LE) and medium (ME) X-ray energies. The most remarkable characteristics of this variability are the regular recurrence of flares at 12000s intervals during a 1-day long ME observation, a dip in the ME flux by a factor of 2 in ∼ 300 s, and variable low-energy absorption in the X-ray spectrum on a timescale of months. The EXOSAT observations support the conclusion reached by Tennant et al. (1981) /1/ on the basis of HEAO-A2 observations that the X-ray behaviour of NGC6814 is unsual among AGN. We consider possible scenarios in which such behaviour may originate, and briefly discuss the issue of a ‘characteristics’ timescale of the variability of AGN.


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    Titel :

    The flux variability of the Seyfert galaxy NGC6814 as observed with exosat


    Beteiligte:

    Erschienen in:

    Erscheinungsdatum :

    1988-01-01


    Format / Umfang :

    4 pages




    Medientyp :

    Aufsatz (Zeitschrift)


    Format :

    Elektronische Ressource


    Sprache :

    Englisch



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