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arXiv · 1102.5016

Quiescent X-ray variability from the neutron star transient Aql X-1

E. M. Cackett·J. K. Fridriksson·J. Homan·J. M. Miller·R. Wijnands
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Abstract

A number of studies have revealed variability from neutron star low-mass X-ray binaries during quiescence. Such variability is not well characterised, or understood, but may be a common property that has been missed due to lack of multiple observations. One such source where variability has been observed is Aql X-1. Here, we analyse 14 Chandra and XMM-Newton observations of Aql X-1 in quiescence, covering a period of approximately 2 years. There is clear variability between the epochs, with the most striking feature being a flare-like increase in the flux by a factor of 5. Spectral fitting is inconclusive as to whether the power-law and/or thermal component is variable. We suggest that the variability and flare-like behaviour during quiescence is due to accretion at low rates which might reach the neutron star surface.

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E. M. Cackett, J. K. Fridriksson, J. Homan, J. M. Miller, R. Wijnands. 2011-02-24. Quiescent X-ray variability from the neutron star transient Aql X-1. https://doi.org/10.1111/j.1365-2966.2011.18601.x

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