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BeppoSAX observation of the eclipsing dipping X-ray binary X1658-298

T. Oosterbroek·A. N. Parmar·L. Sidoli·J. J. M. in 't Zand·J. Heise
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Abstract

Results of a 2000 August 12-13 BeppoSAX observation of the 7.1 hr eclipsing, dipping, bursting, transient, low-mass X-ray binary (LMXRB) X1658-298 are presented. The spectrum outside of eclipses, dips and bursts can be modeled by the combination of a soft disk-blackbody and a harder Comptonized component with a small amount (1.3 10E21 atom/cm2) of low-energy absorption. In contrast, an RXTE observation 18 months earlier during the same outburst, measured an absorption of 5.0 10E22 atom/cm2. Such a change is consistent with a thinning of the accretion disk as the outburst progresses. Structured residuals from the best-fit spectral model are present which are tentatively identified with Ne-K/Fe-L and Fe-K shell emission. The spectral changes during dips are complex and may be modeled by a strong (~3 10E23 atom/cm2) increase in absorption of the Comptonized component only, together with reductions in normalizations of both spectral components. This behavior is in contrast to the ``complex continuum'' model for X-ray dip sources, where the softer blackbody component rapidly suffers strong absorption. It is however, similar to that found during recent XMM-Newton observations of the eclipsing, dipping, LMXRB EXO0748-676.

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T. Oosterbroek, A. N. Parmar, L. Sidoli, J. J. M. in 't Zand, J. Heise. 2001-07-18. BeppoSAX observation of the eclipsing dipping X-ray binary X1658-298. https://doi.org/10.1051/0004-6361%3A20011006

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