Abstract
The BL Lac object Mkn 421 was observed by EXOSAT four times over a period of six days in February 1984. Significant X-ray variability was apparent on a timescale of less than a day, but with no accompanying spectral change. The source exhibited a very soft power law X-ray spectrum with an extremely low intrinsic column density (NH≲1020 cm-2). There was no evidence for an additional hard component attributable to synchrotron self-Compton emission. The observations when combined with other published data imply that significant changes occur in the form of the broad-band UV/X-ray continuum of this source.
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© 1985 D. Reidel Publishing Company, Dordrecht, Holland
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Warwick, R.S., McHardy, I., Pounds, K.A. (1985). EXOSAT Observations of the BL Lac Object MKN 421. In: Peacock, A. (eds) X-Ray Astronomy in the Exosat Era. Springer, Dordrecht. https://doi.org/10.1007/978-94-009-5448-9_80
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DOI: https://doi.org/10.1007/978-94-009-5448-9_80
Publisher Name: Springer, Dordrecht
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