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The Iron K-shell features of MXB 1728-34 from a Simultaneous Chandra-RXTE Observation

A. D' Ai·T. Di Salvo·R. Iaria·M. Mendez·L. Burderi·G. Lavagetto·W. H. G. Lewin·N. R. Robba·L. Stella·M. van der Klis
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Abstract

We report on a simultaneous Chandra and RossiXTE observation of the low-mass X-ray binary atoll bursting source MXB 1728-34 performed on 2002 March 3-5. We fit the 1.2-35 keV continuum spectrum with a blackbody plus a Comptonized component. Large residuals at 6-10 keV can be fitted by a broad (FWHM ~ 2 keV) Gaussian emission line or, alternatively, by two absorption edges associated with lowly ionized iron and Fe XXV/XXVI at ~7.1 keV and ~9 keV, respectively. In this interpretation, we find no evidence of broad, or narrow, emission lines between 6 and 7 keV. We test our alternative modelling of the iron K shell region by reanalysing a previous BeppoSAX observation of MXB 1728-34, finding a general agreement with our new spectral model.

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A. D' Ai, T. Di Salvo, R. Iaria, M. Mendez, L. Burderi, G. Lavagetto, W. H. G. Lewin, N. R. Robba, L. Stella, M. van der Klis. 2005-11-02. The Iron K-shell features of MXB 1728-34 from a Simultaneous Chandra-RXTE Observation. https://arxiv.org/abs/astro-ph/0511072

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