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arXiv · 0812.4519

Orbital Phase Spectroscopy of four High Mass X-ray Binary Pulsars to Study the Stellar Wind of the Companion

Sachindra Naik·Uddipan Mukherjee·Biswajit Paul·C. S. Choi
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Abstract

Our work focuses on a comprehensive orbital phase dependent spectroscopy of the four High Mass X-ray Binary Pulsars (HMXBPs) 4U 1538-52, GX 301-2, OAO 1657-415 & Vela X-1. We hereby report the measurements of the variation of the absorption column density and iron-line flux along with other spectral parameters over the binary orbit for the above-mentioned HMXBPs in elliptical orbits, as observed with the Rossi X-ray Timing Explorer (RXTE) and the BeppoSAX satellites. A spherically symmetric wind profile was used as a model to compare the observed column density variations. Out of the four pulsars, only in 4U 1538-52, we find the model having a reasonable corroboration with the observations, whereas in the remaining three the stellar wind seems to be clumpy and a smooth symmetric stellar wind model appears to be quite inadequate in explaining the data. Moreover, in GX 301-2, neither the presence of a disk nor a gas stream from the companion was validated. Furthermore, the spectral results obtained in the case of OAO 1657-415 & Vela X-1 were more or less similar to that of GX 301-2.

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Sachindra Naik, Uddipan Mukherjee, Biswajit Paul, C. S. Choi. 2008-12-24. Orbital Phase Spectroscopy of four High Mass X-ray Binary Pulsars to Study the Stellar Wind of the Companion. https://doi.org/10.1016/j.asr.2008.12.011

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