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arXiv · 0807.1616

A Swift BAT Look at Super-Orbital X-ray Binaries

Sean A. Farrell·Didier Barret·Gerald Skinner
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Abstract

We present the results of a study with the Swift Burst Alert Telescope in the 14 - 195 keV range of the long-term variability of 5 low mass X-ray binaries with reported or suspected super-orbital periods -- 4U 1636-536, 4U 1820-303, 4U 1916-053, Cyg X-2 and Sco X-1. No significant periodic modulation was detected around the previously reported values in the 4U 1916-053, Cyg X-2 or Sco X-1 light curves. The $\sim$170 d period of 4U 1820-303 was detected up to 24 keV, consistent with the proposed triple system model. The $\sim$46 d period in 4U 1636-536 was detected up to 100 keV, clearly inconsistent with variable photoelectric absorption via a warped precessing disc. We speculate that the appearance of this modulation after 4U 1636-536 entered the low/hard state indicates that this variability could be linked to jet precession such as observed in SS 433.

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Sean A. Farrell, Didier Barret, Gerald Skinner. 2008-07-10. A Swift BAT Look at Super-Orbital X-ray Binaries. https://doi.org/10.1063/1.2945036

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