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arXiv · 2209.07954

Fourier Domain

Matteo Bachetti·Daniela Huppenkothen
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Abstract

The changes in brightness of an astronomical source as a function of time are key probes into that source's physics. Periodic and quasi-periodic signals are indicators of fundamental time (and length) scales in the system, while stochastic processes help uncover the nature of turbulent accretion processes. A key method of studying time variability is through Fourier methods, the decomposition of the signal into sine waves, which yields a representation of the data in frequency space. With the extension into \textit{spectral timing} the methods built on the Fourier transform can not only help us characterize (quasi-)periodicities and stochastic processes, but also uncover the complex relationships between time, photon energy and flux in order to help build better models of accretion processes and other high-energy dynamical physics. In this Chapter, we provide a broad, but practical overview of the most important relevant methods.

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Matteo Bachetti, Daniela Huppenkothen. 2022-09-16. Fourier Domain. https://doi.org/10.1007/978-981-16-4544-0_137-1

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