基于分形布朗运动的斯隆数字巡天中类星体光变特性
Abstract
<p indent="0mm">The optical variability analysis of quasars based on fractal Brownian motion in the Sloan Digital Sky Survey (SDSS). The violent activities of the high energy variability can be observed in multiple wavelength bands of quasars, and studying quasar variability can contribute to a deeper understanding of the physical mechanism of the emission from the central region. Many studies have shown that the great majority of quasar variability is considered to originate in the accretion disk’s thermal emission, but some people do not agree with this view. The Hurst exponent of SDSS quasar variability is calculated using the rescaled range analysis method to investigate the fractal properties of variability in quasars from the SDSS stripe 82. The Hurst exponent results of variability show that the quasar variability is self-similar and long-range correlated. The variability obeys the biased random walk model, and its variation is similar to fractal Brownian motion. The power spectral exponent obtained from the Hurst exponent conversion shows that most of the variabilities can be approximately fitted by the damped random walk model, but a small number of samples have large deviations.</p>
