Correlating time series with spectral results of RXTE data: Observational evidences for four different accretion classes
Abstract
We analyze RXTE/PCA data of black hole and neutron star sources. By analyzing independently the underlying time series (which helps in understanding their nonlinear variabilities) and spectral states, we try to correlate them. Depending on the variation in temporal classes, compact sources exhibit different nonlinear features. Sometimes they show low correlation/fractal dimension, but in other classes or intervals of time they exhibit stochastic nature. This is expected as the accretion flow is a nonlinear system involving magnetohydrodynamics. However, the more conventional way of addressing a compact source is the analysis of its spectral state. What is the connection of nonlinearity to the underlying spectral properties of the flow when the nonlinear properties are related to the associated transport mechanisms describing the geometry of the flow? The talk aims at addressing this question. Based on the connection between observed spectral and nonlinear (time series) properties of two X-ray binaries: GRS 1915+105 and Sco X-1, we attempt to diagnose the underlying accretion modes of the sources in terms of known accretion classes, namely, Keplerian disk, slim disk, advection dominated accretion flow (ADAF) and general advective accretion flow (GAAF). We explore the possible transition of the sources from one accretion mode to others with time. We further confirm that the accretion rate must play an important role in transition between these modes.
- Publication:
-
42nd COSPAR Scientific Assembly
- Pub Date:
- July 2018
- Bibcode:
- 2018cosp...42E2370M