Periodic Variability During the X-ray Decline of 4U 1636-53

Abstract

We report the onset of a large amplitude, statistically significant periodicity (~46 d) in the RXTE/ASM data of the prototype X-ray burster 4U 1636-53, the X-ray flux of which has been gradually declining over the last four years. This behaviour is remarkably similar to that observed in the neutron star LMXB KS 1731-260, which is a long-term transient. We also report on an INTEGRAL/IBIS observation of 4U 1636-53 during its decline phase, and find that the hard X-ray flux (20-100 keV) indicates an apparent anti-correlation with soft X-rays (2-12 keV). We argue that 4U 1636-53 is transiting from activity to quiescence, as occurred in KS 1731-260. We also suggest that the variability during the X-ray decline is the result of an accretion rate variability related to the X-ray irradiation of the disc.

arXiv comment6 pages. Accepted by MNRAS

References in corpus (10)

• First Results from the All-Sky Monitor on the Rossi X-ray Timing Explorer
• The Properties of X-Ray and Optical Light Curves of X-Ray Novae
• X-ray irradiation in low mass binary systems
• XMM-Newton observations of the neutron star X-ray transient KS 1731-260 in quiescence
• On the Correlated Spectral and Timing Properties of 4U 1636-53: an Atoll Source at High Accretion Rates
• A0620-00 revisited: a black-hole transient case-study
• Spin Down of Pulsations in the Cooling Tail of an X-ray Burst from 4U 1636-53
• High-energy observations of the state transition of the X-ray nova and black hole candidate XTE J1720-318
• The origin of the rebrightening in soft X-ray transient outbursts
• Possible 38 day X-ray period of KS1731-260

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