Low-Frequency Quasi-Periodic Oscillations in the X-ray Nova MAXI J1535-571 at the Initial Stage of Its 2017 Outburst

Understand

We report the discovery of low-frequency quasi-periodic oscillations (QPOs) in the power spectrum of the X-ray nova MAXI J1535-571 at the initial stage of its outburst in September 2017.

• Based on data from the SWIFT and INTEGRAL instruments, we have traced the evolution of the QPO parameters (primarily their frequency) with time and their correlation with changes in the X-ray spectrum of the source (changes in the emission flux and hardness).
• We place constraints on the theoretical QPO generation models.