Periodicities in X-ray Binaries from Swift/BAT Observations

Abstract

The Burst Alert Telescope (BAT) on board Swift has accumulated extensive light curves for 265 sources (not including GRBs) in the energy range 14 to 200 keV. We present here a summary of searches for periodic modulation in the flux from X-ray binaries. Our results include: determination of the orbital periods of IGR J16418-4532 and IGR J16320-4751; the disappearance of a previously known 9.6 day period in 4U 2206+54; the detection of a 5 hour period in the symbiotic X-ray binary 4U 1954+31, which might be the slowest neutron star rotation period yet discovered; and the detection of flares in the supergiant system 1E 1145.1-6141 which occur at both periastron and apastron passage with nearly equal amplitude. We compare techniques of weighting data points in power spectra and present a method related to the semi-weighted mean which, unlike conventional weighting, works well over a wide range of source brightness.

To appear in the proceedings of "The Extreme Universe in the Suzaku Era", Kyoto, Japan, December 4-8, 2006. (Progress of Theoretical Physics, Supplement)

Cited by in corpus (6)

• Cosmological implications of the composite spectra of galactic X-ray binaries constructed using MAXI data
• Diverse Long-Term Variability of Five Candidate High-Mass X-ray Binaries from Swift Burst Alert Telescope Observations
• A Study of the 20 Day Superorbital Modulation in the High-Mass X-ray Binary IGR J16493-4348
• Investigating the superorbital modulations in 4U 1909+07, IGR J16418-4532 and IGR J16479-4514 with Swift XRT, BAT and NuSTAR observations
• Multi-wavelength observations of the Be/X-ray binary IGR J01217-7257 (=SXP 2.16) during outburst
• Swift/XRT monitoring of the orbital and superorbital modulations in 4U 1909+07