Time domain methods for X-ray and gamma-ray astronomy

Abstract

A variety of statistical methods for understanding variability in the time domain for low count rate X-ray and gamma-ray sources are explored. Variability can be detected using nonparametric (Anderson-Darling and overdispersion tests) and parametric (sequential likelihood-based tests) tools. Once detected, variability can be characterized by nonparametric (autocorrelation function, structure function,wavelet analysis) and parametric (multiple change point model such as Bayesian Blocks, integer autoregressive models, C-statistic and Poisson regression) methods. New multidimensional variability detection approaches are outlined. Software packages designed for high energy data analysis are deficient but tools are available in the R statistical software environment. Most of the methods presented here are not commonly used in high energy astronomy.

26 pages, 9 figures. To appear in Handbook for X-ray and Gamma-Ray Astrophysics, Volume 4: Analysis techniques, Section XVIII: Timing Analysis (Belloni & Bhattacharya, eds., Springer)

References in corpus (4)

• X-ray Super-Flares From Pre-Main Sequence Stars: Flare Energetics And Frequency
• Exploring the Long-Term Evolution of GRS 1915+105
• A Swift study of long-term changes in the X-ray flaring properties of Sagittarius A*
• eBASCS: Disentangling Overlapping Astronomical Sources II, using Spatial, Spectral, and Temporal Information