A study on the long term periodicities among the X‐ray binaries: Two new superorbital periods

Abstract

Long term behaviours of a few selected X-ray binaries are studied on the basis of RXTE/ASM archive covering a period of ∼13 years of continuous X-ray data. Two new superorbital periods seem to be revealed for the GX354-0 and X Persei systems as 8.7 years and 345 days, respectively. Although the X Persei system has two strongest peaks in its power density spectrum at 15.7 years and at 345 days, the latter is much more plausible. The GX354-0 system also has few additional periodicities appeared in different time intervals.

Characterizing X-ray binary long-term variability

“…The DPS shows a P sup ∼ 63 and ∼72 d are both initially detected, and rapidly replaced by a single period between those values. The strongest detections are towards the end of the data set where a ∼50 d period evolves towards ∼70 d. The source also clearly displays very long term variability on a ∼decade long time‐scale (Kotze & Charles 2010; Özdemir 2010), which is not believed to be associated with the accretion disc properties.…”