Fluctuation analysis of stellar x-ray binary systems

Abstract

We study time series of x-ray sources of 129 stellar binary systems present in the public data collected by the instrument All Sky Monitor on board of the satellite Rossi X-Ray Timing Explorer. The light time series was analyzed by applying detrended fluctuation analysis to estimate the long-range power-law correlation exponents α. The scaling exponent was calculated for all systems and its value indicated a signature of each kind of system, i.e., whether flare takes place (with α=1.22) or not (with α=0.64). As a consequence, our results may identify the stability of the systems from the scaling exponent α value, for instance, if α∼0.5 (white noise) the system is stable and unstable when α≠0.5 (long-range power-law correlation).