Speaker
Description
The study of X-ray binaries has been fundamentally transformed by spectral-timing techniques, which bridge the gap between energy spectra and fast variability to map the innermost regions of accreting compact objects. By exploring the complex interplay between photons of different energies and their arrival times, these methods provide unique constraints on the geometry, dynamics, and physical processes driving accretion flows and corona evolution.
In this talk, I will review the core methodology behind spectral-timing analysis, focusing on GHATS (General High-energy Aperiodic Time-series Software). Conceived by Tomaso's vision in the era of RXTE, GHATS has evolved into a multi-mission tool, enabling advanced timing analysis across several generations of X-ray observatories, from XMM-Newton and NuSTAR to NICER, Astrosat, and Insight-HXMT. I will highlight its capabilities in resolving accretion tones through key Fourier products, such as power density spectra, cross-spectra, dynamical power spectra, phase lags, and intrinsic coherence.
Finally, I will discuss the crucial physical insights these techniques have yielded across both black hole and neutron star systems, with particular emphasis on low- and high-frequency quasi-periodic oscillations, celebrating Tomaso’s profound and lasting legacy in high-time-resolution X-ray astronomy.