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Discovery of an X-Ray Off-State in the Supersoft Source CAL 83

Published online by Cambridge University Press:  12 April 2016

P. Kahabka*
Affiliation:
Astronomical Institute and Center for High Energy Astrophysics, University of Amsterdam, Kruislaan 403, NL-1098 SJ Amsterdam

Abstract

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An X-ray off state of CAL 83 has been observed in April 1996 with the ROSAT HRI three weeks after a normal on state. An upper limit for a linear decline time of the observed flux of ~20 days (and of an efolding decline time of ~6 days) is deduced. This decline may be due to the response of the white dwarf envelope to a temporary increased mass accretion rate giving rise to an envelope expansion. CAL 83 may resemble the recurrent supersoft LMC transient RX J0513.9–6951 with episodes of disappearance in X-rays.

Type
Part 15. Poster Papers
Copyright
Copyright © Astronomical Society of the Pacific 1997

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