Pulse frequency changes of 1E 2259+586 and the binary interpretation

Pulse frequencies from the archival ROSAT observations of 1E 2259+586 are presented. A short-term spin-up episode superposed on the secular spin-down trend is observed. Combining the previously published pulse frequencies, we estimate the variance of the angular velocity over a 15 yr span of observations. The level of fluctuations in angular velocity is similar to that of established accreting binary neutron stars. These results favor accretion by a neutron star from a very low mass companion as the source of the X-ray luminosity, although accretion by a solitary neutron star from a residual disk might be possible.


Pulse phase resolved x-ray spectroscopy of four accretion powered millisecond pulsars
Çolak, Sıdıka Merve; Baykal, Altan; Department of Physics (2014)
In this thesis, pulse phase resolved X-ray spectroscopy of four accretion powered millisecond pulsars which are IGR J00291+5934 , IGR J17498-2921 , XTE J0929-314 and XTE J1807-294 will be presented. Phase dependent changes during their outbursts will be checked for possible correlations of spectral parameters such as photon index and blackbody temperature with rotation phase using archive of Rossi X-ray Timing Explorer (RXTE) observations. In the analysis of IGR J17498-2921 in 2011 outburst , positive corre...
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 spectrum and dips of RE 0751+14: A joint evaluation of ROSAT and ASCA archival data
Kiziloglu, U; Baykal, Altan; Alev, M; Gogus, E (1998-01-01)
Using archival ASCA and ROSAT observations of RE 0751+14, X-ray energy spectra, pulse profiles and the results of pulse timing analysis are presented. The energy spectra are well-fitted by a blackbody model at low energy and a Raymond-Smith model at high energy, together with a partial covering absorber. A fluorescence emission line at 6.4 keV with an equivalent width similar to 220 eV was resolved for the first time.
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 ...
The pulse frequency noise of magnetars and persistent accretion powered pulsars
Serim, Danjela; Baykal, Altan; Department of Physics (2021-2-03)
In this thesis, the pulse frequency fluctuations of magnetars and six selected persis-tent accreting powered pulsars (PAPPs) are presented. Using the data fromRXTE,XMM-Newton, Chandra, SwiftandFERMIobservatories, the timing noise behav-ior of individual sources on various timescales are examined, depending on the datasampling rate of input frequency measurements. The timing noise amplitudes are an-alyzed via two separate methods, namely∆8andr.m.smethods. The timing noisecharacteristics of both magne...
Citation Formats
A. Baykal, “Pulse frequency changes of 1E 2259+586 and the binary interpretation,” ASTROPHYSICAL JOURNAL, pp. 470–477, 1996, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/48212.