X-ray flux and pulse frequency changes of three high mass X-ray binary pulsars: Vela X-1, GX 301-2 and OAO 1657-415

Date

2000-01-01

Author

Inam, SC
Baykal, Altan

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

214
views

0
downloads

Using archival BATSE (Burst and Transient Source Experiment) 20-50 keV band X-ray flux and pulse frequency time series, we look for correlations between torque, luminosity and specific angular momentum for three high mass X-ray binary pulsars Vela X-1, GX 301-2 and OAO 1657-415. Our results show that there is no correlation between pulse frequency derivative and flux which may be an indication of the absence of stable prograde accretion disk. From the strong correlation of specific angular momentum and torque, we conclude that the accretion geometry changes continuously as suggested by the hydrodynamic simulations (Blondin et al. 1990).

Subject Keywords

X-rays : stars, Stars : pulsars : individual : Vela X1, Stars : pulsars : individual : GX 301-2, Stars : pulsars : individual : OAO 1657-415, Accretion, Accretion disks

URI

https://hdl.handle.net/11511/53893

Journal

ASTRONOMY & ASTROPHYSICS

Collections

Department of Physics, Article

Suggestions

OpenMETU
Core

Frequency Resolved Spectroscopy of XB 1323-619 and EXO 0748-676 Balman, Şölen (2009-09-11) We present the frequency resolved energy spectra (FRS) of the low-mass X-ray binary dipper XB 1323-619 and EXO 0748-676 using archival XMM-Newton observations. The FRS of XB 1323-619 is well described by a single blackbody component with kT in a range 1.2-1.6 keV. We attribute this to an existing boundary layer, the likely source of the soft emission, supported by radiation pressure. We detect a different form of FRS for the frequency ranges 0.9-6 Hz and 8-30 Hz which is modeled best with a power law and a ...
Comprehensive timing and X-ray spectral analysis of GX 1+4 Serim, M. M.; Sahiner, S.; Cerri-Serim, D.; İNAM, SITKI ÇAĞDAŞ; Baykal, Altan (2017-08-01) We present the analysis of RXTE-PCA observations of GX 1+4 between 2001 March 3 and 2003 January 31 together with the CGRO-BATSE X-ray flux and frequency derivative time series between 1991 and 1999. From the timing analysis of RXTE-PCA observations, we are able to phase connect pulse arrival times of the source within two different time intervals and obtain corresponding timing solutions. Using these pulse arrival times, we contribute to long-term pulse frequency history of the source. We look for episodic...
Recent Spin Rate Measurements of 4U 1907+09 Sahiner, S.; İNAM, SITKI ÇAĞDAŞ; Baykal, Altan (2010-08-06) In this study, X-ray spectral and pulse timing analysis of the high mass X-ray binary (HMXB) pulsar 4U 1907+09, based on the observations with RXTE are presented. Spin rate measurements indicate a new spin-down episode with a rate close to the previous steady spin-down rate. Orbital phase resolved spectroscopy reveals that the Hydrogen column density varies through the orbit reaching to its maximum value just after periastron. A slight spectral softening with increasing luminosity is aslo observed.
The torque and X-ray flux changes of OAO 1657-415 Baykal, Altan (1997-03-01) Combining previously published pulse frequencies and BATSE measurements, we estimate the noise strengths (or power density estimates) of angular accelerations by using the root mean square residuals of angular velocity time series of OAO 1657-415 and present the power spectra. The statistical interpretation of the angular velocity fluctuations is consistent with a random walk model. In order to investigate the short term angular velocity fluctuations in detail, a structure function analysis is applied for a...
X-ray analysis of high mass x-ray binary pulsars Şahiner, Şeyda; Baykal, Altan; İnam, Sıtkı Çağdaş; Department of Physics (2015) In this thesis, X-ray properties of three high mass X-ray binary (HMXB) pulsars are analysed, using the data of X-ray satellites such as RXTE, INTEGRAL and Swift. Selected sources belong to different subgroups of the HMXB family. The first system, 4U 1907+09 is a classical wind-fed supergiant system with persistent X-ray emission; although it shows irregular flares and dips. SWIFT J1729.9-3437 and SWIFT J0513.4-6547 are newly discovered transient systems. Although the counterpart of SWIFT J1729.9-3437 could...

Citation Formats

S. Inam and A. Baykal, “X-ray flux and pulse frequency changes of three high mass X-ray binary pulsars: Vela X-1, GX 301-2 and OAO 1657-415,” ASTRONOMY & ASTROPHYSICS, pp. 617–623, 2000, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/53893.