X-ray analysis of high mass x-ray binary pulsars

Şahiner, Şeyda
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 not be detected, its properties are in agreement with highly obscured wind-fed supergiant systems. SWIFT J0513.4-6547 resides in a Be X-ray binary system. Timing studies of 4U 1907+09 shows that the pulsar entered to a new spin-down episode during the 4.5 years of monitoring campaign. Pulse period fluctuations of the source are consistent with noise processes implying a random walk. Orbital variations in spectral parameters and occurrence of dip states are also examined. Results show that the probability of observing a dip state is higher for certain orbital phases. The column density is also changing with orbital period, giving clues on the geometry of the accretion and the structural properties of the matter. Outburst observations of SWIFT J1729.9-3437 are used to identify the timing and spectral properties of the source. The pulse frequency and its derivative are measured as 1.8734(8)x10^{-3} Hz and 6.42(6)x10^{-12} Hz/s, respectively. In addition a possible orbital period is detected as 15.3 days. The pulse and orbit periods place SWIFT J1729.9-3437 among the wind-fed supergiant systems in the Corbet diagram. Furthermore, X-ray spectrum, defined by a power law with a high energy cut-off, is highly absorbed (n_H = 8.27x10^{22} cm^{-2}). The two outbursts from SWIFT J0513.4-6547 are investigated for temporal and pulse-phase dependent variations in X-ray spectral properties. Two different models equally fit well the overall spectrum of 2009 outburst, however spectral parameters are unusual for both. A power law with a high energy cut-off model gives the lowest cut-off energy (E_{cut} = 5.04 keV) among HMXBs, where as a power law plus blackbody model gives the highest blackbody temperature (kT = 1.89 keV).


X-ray and optical observations of high mass x-ray binaries
Beklen, Elif; Baykal, Altan; İnam, Çağdaş; Department of Physics (2010)
In this thesis, X-ray and optical observations of accretion powered pulsars are presented. By using archival RXTE observations we work on the X-ray spectral and pulse timing analysis of 4U 1538-52, 4U 1907+09, SMC X-1 to have more detailed information about their orbital and spin parameters. For 4U 1538-52 and SMC X-1, we determined new orbital epochs. By using long term pulse history of 4U 1907+09, we were able to work spin-down trend of the system and also calculate the change in the spin-down rate. Using...
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
Inam, SC; Baykal, Altan (2000-01-01)
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 torq...
X-ray timing properties of four anomalous x-ray pulsars: 4u 0142+61, 1e 2259+586, 1rxs j170849.0_400910, and 1e 1841_045
Çerri, Danjela; Baykal, Altan; İnam, Sıtkı Çağdaş; Department of Physics (2015)
In this thesis, the detailed X-ray timing characteristics of four Anomalous X-Ray Pulsars (AXPs); 4U 0142+61, 1E 2259+586, 1RXS J170849.0 -400910, and 1E 1841- 045 are presented for glitch free time intervals using data taken by Rossi X-Ray Timing Explorer (RXTE). The pulse arrival times of these AXPs are evaluated by phase coherent timing method. After the removal of the spin-down trend from pulse arrivals, remaining residuals are used for estimation of their noise strengths. Possible correlation of the no...
X-ray spectral and timing studies of the high mass x-ray binary pulsar 4u 1907+09
Şahiner, Şeyda; Baykal, Altan; Department of Physics (2009)
In this thesis, X-ray spectral and pulse timing analysis of the high mass X-ray binary pulsar 4U 1907+09, based on the observations with Rossi X-ray Timing Explorer (RXTE) and International Gamma-Ray Astrophysics Laboratory (INTEGRAL), are presented. INTEGRAL (October 2005 - November 2007) and RXTE (June 2007 - December 2008) observations confirm that the luminosity of the source is highly variable such that, flaring and dipping activities are observed. The results of time-averaged energy spectra of RXTE an...
Pulse timing studies of X-ray binaries: GX1+4,SWIFT J0513.4-6547, X Persei and SXP 1062
Serim, Muhammed Miraç; Baykal, Altan; İnam, Sıtkı Çağdaş; Department of Physics (2019)
This thesis focuses on X-ray timing properties of four different X-ray binary systems, based on archival data of the X-ray missions RXTE, Swift, XMM-Newton, Chandra and Integral. One of the selected sources is a LMXB system GX 1+4 while remaining sources are BeXB systems: SWIFT J0513.4-6547, X Persei and SXP 1062. For GX 1+4, the timing analysis of RXTE-PCA observations between 2001 March 3 and 2003 January 31 are presented. The timing solutions of two different time intervals are constructed. Futhermore, w...
Citation Formats
Ş. Şahiner, “X-ray analysis of high mass x-ray binary pulsars,” Ph.D. - Doctoral Program, Middle East Technical University, 2015.