A study of temeporal characteristics of selected Cataclysmic Variables: The broad-band noise structure between 2-20 kev

2005-09-30
Balman, Şölen
Kulebi, B
Beklen, E
We present the preliminary analysis of the band-limited noise structure of Cataclysmic Variables (CVs) in the 220 keV energy band. We have currently analyzed Rossi X-ray Timing Explorer (RXTE) PCA data and derived time series from 30 CVs using the RXTE archive. In general, CVs of different types all show broad band noise which can be fitted with power laws, using exponential cut-offs, and Lorenzians in a similar way to power spectral (noise) characteristics of X-ray Binaries (XRBs). In general terms the power spectra show a power law index of (-)1.2-2. A rather large scale flattening of the power spectra exits in nonmagnetic systems in the low to very low frequency range. We observe that in low and high states/outbursts the noise in the high frequency range and low frequency range is changed. CVs show considerable very low frequency noise. In addition, we have recovered several possible QPOs in the X-ray wavelengths from CVs mainly from Intermediate Polar systems.
Symposium on the X-ray Universe 2005

Suggestions

A study of selected low-mass X-ray binary dip sources observed with INTEGRAL
Balman, Şölen (2007-08-17)
I present archival data of the dipping LMXB systems, XB 1916-053, XB 1323-619, X1624-490, and 4U 1746-371obtained by the ISGRI and JEM-X detectors on-board the INTEGRAL Observatory. The spectral parameters derived from the fits to the data are consistent with hot coronal regions in these systems where the electron temperatures are in a range 4.9-18.8 keV with the exception of XB 1323-62 having an unbounded temperature. The optical depth to Compton scattering, tau is low and consistent with electron densitie...
A comprehensive study of RXTE and INTEGRAL observations of the X-ray pulsar 4U 1907+09
Sahiner, S.; İNAM, SITKI ÇAĞDAŞ; Baykal, Altan (2012-04-01)
We analyse observations of the accretion-powered pulsar 4U 1907+09 from the International Gamma-Ray Astrophysics Laboratory (INTEGRAL; between 2005 October and 2007 November) and from the Rossi X-ray Timing Explorer (RXTE; between 2007 June and 2011 March). Using observations from the Imager on-board the INTEGRAL satellite (IBIS), the INTEGRAL Soft Gamma-Ray Imager (ISGRI) and the RXTE Proportional Counter Array (PCA), we update the pulse period history of the source. We construct power spectrum density of ...
Modelling of quasi-periodic oscillations with wave packets
Alpar, MA; Yilmaz, A (1997-01-01)
Model dispersion relations are introduced to explore power spectra of the normal-branch (NB) and horizontal-branch (HB) quasi-periodic oscillations (QPOs; for reviews see Van der Klis (1989)[ARA&A, 27, 517], (1992) [Proc. of NATO ASI X-Ray Binaries and Recycled Pulsars, eds. E.P.J. Van den Heuvel & S.A. Rappaport, Kluwer, Dordrecht], (1995)[Proc, of NATO ASI The Lives of the Neutron Stars, eds. M.A. Alpar, Omit Kiziloglu, & J. van Paradijs, Kluwer, Dordrecht]) of low mass X-ray binaries (LMXBs) in terms of ...
The broad-band noise characteristics of selected AXPs and SGRs: Probing the magnetar coronae
Kulebi, Baybars; Balman, Şölen (2007-08-17)
We present the broad-band noise structure of Anomalous X-Ray Pulsars (AXPs) and Soft Gamma Repeaters (SGRs) in the 2-60 keV energy band which are thought to be powered by either magnetic decay(Thompson & Duncan 1995) or accretion (Alpar 2001). We have used Rossi X-ray Timing Explorer (R-XTE) PCA archival light curves and derived time series for 4 AXPs and 1 SGR. We detect that AXP and SGR sources show band limited noise at low frequencies in the range 0.005-0.05 Hz. We find that this noise level can be asso...
A Numerical Study of a Modular Sparse Grad-Div Stabilization Method for Boussinesq Equations
Demir, Medine; Kaya Merdan, Songül (2019-10-10)
This study presents a modular sparse grad-div stabilization method for solving the Boussinesq equations. Unlike the usual grad-div stabilization which produces fully coupled block matrices, the proposed stabilization method produces block upper triangular matrices. Thus, the proposed method is more attractive in terms of both its computational cost and solution accuracy. We provide unconditional stability results for velocity and temperature. Two numerical experiments are performed to demonstrate the effici...
Citation Formats
Ş. Balman, B. Kulebi, and E. Beklen, “A study of temeporal characteristics of selected Cataclysmic Variables: The broad-band noise structure between 2-20 kev,” El Escorial, Spain, 2005, vol. 604, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/54907.