A systematic study of the phase difference between QPO harmonics in black hole X-ray binaries

Understand

We perform a systematic study of the evolution of the waveform of black hole X-ray binary low-frequency QPOs, by measuring the phase difference between their fundamental and harmonic features.

• This phase difference has been studied previously for small number of QPO frequencies in individual sources.
• Here, we present a sample study spanning fourteen sources and a wide range of QPO frequencies.
• With an automated pipeline, we systematically fit power spectra and calculate phase differences from archival Rossi X-ray Timing Explorer (RXTE) observations.