The broad-band noise characteristics of selected AXPs and SGRs: Probing the magnetar coronae

Kulebi, Baybars
Balman, Şölen
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 associated with their bursts, glitches or flaring activities. We discover band-limited red noise in 1E 2259+586 only for about two years after its outburst and the associated glitch. The system shows no broad-band noise otherwise. The other three AXPs indicate a lower band-limited noise level in comparison with 1E 2259+586 and it is persistent, but show variations. We favour a model where this broad-band noise particularly as detected in 1E 2259+586 is related to the Compton scattering of thermal photons in the magnetar corona and thus reveal coronal time scales and activity.
AIP Conference: 40 Years of Pulsars


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Citation Formats
B. Kulebi and Ş. Balman, “The broad-band noise characteristics of selected AXPs and SGRs: Probing the magnetar coronae,” Montreal, CANADA, 2007, vol. 983, Accessed: 00, 2020. [Online]. Available: