Open AccessTiming studies on RXTE observations of SAX J2103.5+4545
Author(s) -
Baykal A.,
İnam S. Ç.,
Stark M. J.,
Heffner C. M.,
Erkoca A. E.,
Swank J. H.
Publication year - 2007
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2006.11231.x
Subject(s) - physics , astrophysics , flux (metallurgy) , pulsar , spectral line , orbital elements , pulse (music) , power law , noise (video) , astronomy , optics , statistics , computer science , metallurgy , materials science , mathematics , artificial intelligence , detector , image (mathematics)
SAX J2103.5+4545 has been continuously monitored for ∼900 d by the Rossi X‐ray Timing Explorer ( RXTE ) since its outburst in 2002 July. Using these observations and previous archival RXTE observations of SAX J2103.5+4545, we refined the binary orbital parameters and find the new orbital period as P = (12.665 36 ± 0.000 88) d and the eccentricity as 0.4055 ± 0.0032. With these new orbital parameters, we constructed the pulse frequency and pulse frequency derivative histories of the pulsar and confirmed the correlation between X‐ray flux and pulse frequency derivative presented by Baykal, Stark & Swank. We constructed the power spectra for the fluctuations of pulse frequency derivatives and found that the power‐law index of the noise spectra is 2.13 ± 0.6. The power‐law index is consistent with random walk in pulse frequency derivative and is the steepest among the HMXRBs. X‐ray spectra analysis confirmed the inverse correlation trend between power‐law index and X‐ray flux found by Baykal et al.