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Record 2 of 22
Long-Term Properties of Accretion Discs in X-ray Binaries. 1; The Variable Third Period in SMC X-1
Author and Affiliation:
Charles, P. A.
Clarkson, W. I.
Coe, M. J.
Laycock, S.
Tout, M.
Wilson, C.
Six, N. Frank [Technical Monitor]
Abstract: Long term X-ray monitoring data from the RXTE All Sky Monitor (ASM) reveal that the third (superorbital) period in SMC X-1 is not constant but varies between 40-60 days. A dynamic power spectrum analysis indicates that the third period has been present continuously throughout the five years of ASM observations. This period changed smoothly from 60 days to 45 days and then returned to its former value, on a timescale of approximately 1600 days. During the nearly 4 years of overlap between the CGRO & RXTE missions, the simultaneous BATSE hard X-ray data confirm this variation in SMC X-1. Sources of systematic error and possible artefacts are investigated and found to be incapable of reproducing the results reported here. Our disco cry of such an instability in the superorbital period of SMC X-1 is interpreted in the context of recent theoretical studies of warped, precessing accretion discs. We find that the behaviour of SMC X-1 is consistent with a radiation - driven warping model.
Publication Date: Jan 01, 2002
Document ID:
20020067790
(Acquired Sep 06, 2002)
Subject Category: GEOPHYSICS
Document Type: Preprint
Financial Sponsor: NASA Marshall Space Flight Center; Huntsville, AL United States
Organization Source: NASA Marshall Space Flight Center; Huntsville, AL United States
Southampton Univ.; Dept. of Physics and Astronomy; United Kingdom
Description: 1p; In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: Copyright
NASA Terms: X RAYS; BINARY STARS; DATA ACQUISITION; SPECTRUM ANALYSIS; GAMMA RAY BURSTS; X RAY TIMING EXPLORER; SYSTEMATIC ERRORS; GAMMA RAY OBSERVATORY
Availability Source: Other Sources
Availability Notes: Abstract Only
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