Recent Timing Studies on RXTE Observations of 4U 1538-52

Abstract

The high mass X-ray binary pulsar 4U 1538-52 was observed between July 31 and August 7, 2003. Using these observations, we determined new orbital epochs for both circular and elliptical orbit models. The orbital epochs for both orbit solutions agreed with each other and yielded an orbital period derivative $\dot{P}/P=(0.4\pm 1.8)\times 10^{-6}$ yr${}^{-1}$. This value is consistent with the earlier measurement of $\dot{P}/P=(2.9\pm 2.1)\times 10^{-6}$ yr${}^{-1}$ at the $1\sigma$ level and gives only an upper limit to the orbital period decay. Our determination of the pulse frequency showed that the source spun up at an average rate of $2.76\times 10^{-14}$ Hz sec${}^{-1}$ between 1991 and 2003.

Revised version. Accepted for publication in A&A

References in corpus (1)

• Orbital Decay in LMC X-4

Cited by in corpus (12)

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• Superorbital Modulation in the High-Mass X-ray Binary 4U 1538-52, and Possible Modulation in IGR J16393-4643
• Orbital phase resolved spectroscopy of 4U1538-52 with MAXI
• Torque reversal and cyclotron absorption feature in HMXB 4U 1538-522
• Pulse Frequency Fluctuations of Persistent Accretion Powered Pulsars
• Eclipse Timings of the LMXB XTE J1710-281 : Discovery of a third orbital period glitch
• Exploring polarization and geometry in the X-ray pulsar 4U 1538-52
• Spectroscopic modelling of two high-mass X-ray binaries, Cyg X--3 and 4U 1538--522