Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
The broad-band noise characteristics of selected cataclysmic variables (CVS), anomalous x-ray pulsars (AXPS) and soft gamma repeaters (SGRS)
Download
index.pdf
Date
2006
Author
Külebi, Baybars
Metadata
Show full item record
Item Usage Stats
209
views
74
downloads
Cite This
In this work present the broad-band noise structure in the 2-60 keV data of Cataclysmic Variables (CVs) with Anomalous X-Ray Pulsars (AXPs) and Soft Gamma Repeaters (SGRs). We analyzed Rossi X-ray Timing Explorer (RXTE) PCA data and derived time series from 27 CVs, 4 AXPs and 1 SGR using the RXTE archive. In general, CVs of different types all show broad band noise which can be fitted with power laws, using exponentional cut-offs, and Lorentzians 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 considerably low frequency noise. In addition, we recovered several possible QPOs in the X-ray wavelengths from CVs mainly from Intermediate Polar systems. AXP and SGR sources which are thought to be powered by either magnetic decay or accretion show band limited noise in their low frequencies. We also correlated their equal time interval noise characteristic with their burst states and discovered that in the two AXPs (1E 2259+586, 1E 1048.1-5937) noise correlates with their bursts.
Subject Keywords
Stars.
URI
http://etd.lib.metu.edu.tr/upload/12608117/index.pdf
https://hdl.handle.net/11511/16577
Collections
Graduate School of Natural and Applied Sciences, Thesis
Suggestions
OpenMETU
Core
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...
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...
On period and burst histories of AXPs and SGRs and the possible evolution of these objects on the P-P diagram
Guseinov, OH; Yazgan, EFE; Ankay, A; Tagieva, S (World Scientific Pub Co Pte Lt, 2003-01-01)
In this paper, timing data for anomalous X-ray pulsars and soft gamma repeaters are compiled. Timing properties of these objects are investigated. The effect of bursts of soft gamma repeaters on their period history is investigated. The P-P diagram for pulsars, X-ray binaries, anomalous X-ray pulsars, soft gamma repeaters and dim radio quiet neutron stars is constructed. The possible evolutionary tracks for anomalous X-ray pulsars, soft gamma repeaters and dim radio quiet neutron stars are examined.
THE NOISE IN THE 35-D CYCLE OF HER X-1
Baykal, Altan; DEETER, JE; SCOTT, DM (1993-11-15)
We calculate the power density spectrum of fluctuations in the X-ray turn-on times of Her X-1, including new data which extend the X-ray and optical flux observations to a span of over 20 yr with 221 distinct 35-d high-low flux cycles. If we assume that turn-on times define the period of the 35-d clock, this statistical interpretation of turn-on behaviour is consistent with a white-noise process in the first derivative of the 35-d phase fluctuations (or a random walk in clock phase). We discuss the implicat...
The re-analysis of the ROSAT data of Nova Mus 1983 using white dwarf atmosphere emission models
Balman, Şölen; Krautter, J (2001-10-01)
The analyses of X-ray emission from classical novae during the outburst stage have shown that the soft X-ray emission below 1 keV, which is thought to originate from the photosphere of the white dwarf, is inconsistent with the simple blackbody model of emission. Thus, ROSAT Position Sensitive Proportional Counter (PSPC) archival data of the classical Nova Mus 1983 (GQ Mus) have been re-analysed in order to understand the spectral development in the X-ray wavelengths during the outburst stage. The X-ray spec...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
B. Külebi, “The broad-band noise characteristics of selected cataclysmic variables (CVS), anomalous x-ray pulsars (AXPS) and soft gamma repeaters (SGRS),” M.S. - Master of Science, Middle East Technical University, 2006.
