Chandra Observations of the Faintest Low-Mass X-ray Binaries

Colleen. A. Wilson; Sandeep K. Patel; Chryssa Kouveliotou; Peter G. Jonker; Michiel van der Klis; Walter H. G Lewin; Tomaso Belloni; Mariano Mendez

doi:10.1086/377473

arXiv · astro-ph/0307045

Chandra Observations of the Faintest Low-Mass X-ray Binaries

Colleen. A. Wilson·Sandeep K. Patel·Chryssa Kouveliotou·Peter G. Jonker·Michiel van der Klis·Walter H. G Lewin·Tomaso Belloni·Mariano Mendez

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Abstract

There exists a group of persistently faint galactic X-ray sources that, based on their location in the galaxy, high L_x/L_opt, association with X-ray bursts, and absence of low frequency X-ray pulsations, are thought to be low-mass X-ray binaries (LMXBs). We present results from Chandra observations for eight of these systems: 4U 1708-408, 2S 1711-339, KS 1739-304, SLX 1735-269, GRS 1736-297, SLX 1746-331, 1E 1746.7-3224, and 4U 1812-12. Locations for all sources, excluding GRS 1736-297, SLX 1746-331, and KS 1739-304 (which were not detected) were improved to 0.6" error circles (90% confidence). Our observations support earlier findings of transient behavior of GRS 1736-297, KS 1739-304, SLX 1746-331, and 2S 1711-339 (which we detect in one of two observations). Energy spectra for 4U 1708-408, 2S 1711-339, SLX 1735-269, 1E 1746.7-3224, and 4U 1812-12 are hard, with power law indices typically 1.4-2.1, which are consistent with typical faint LMXB spectra.

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Colleen. A. Wilson, Sandeep K. Patel, Chryssa Kouveliotou, Peter G. Jonker, Michiel van der Klis, Walter H. G Lewin, Tomaso Belloni, Mariano Mendez. 2003-07-02. Chandra Observations of the Faintest Low-Mass X-ray Binaries. https://doi.org/10.1086/377473

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