A model for 3:2 HFQPO pairs in black hole binaries based on cosmic battery

TL;DR

This paper proposes a new model for 3:2 high-frequency QPO pairs in black hole binaries based on magnetic connections driven by the cosmic battery, explaining observed phenomena and overcoming damping issues.

Contribution

It introduces a novel model linking epicyclic resonances, magnetic connection, and cosmic battery effects to explain HFQPOs in black hole binaries.

Findings

The model fits observed 3:2 HFQPO pairs in four BHXBs.

Magnetic connection via cosmic battery can overcome damping in resonance.

Magnetic fields influence state transitions in black hole binaries.

Abstract

A model for 3:2 high-frequency quasi-periodic oscillations (HFQPOs) with 3:2 pairs observed in four black hole X-ray binaries (BHXBs) is proposed by invoking the epicyclic resonances with the magnetic connection (MC) between a spinning black hole (BH) with a relativistic accretion disc. It turns out that the MC can be worked out due to Poynting-Robertson cosmic battery (PRCB), and the 3:2 HFQPO pairs associated with the steep power-law states can be fitted in this model. Furthermore, the severe damping problem in the epicyclic resonance model can be overcome by transferring energy from the BH to the inner disc via the MC process for emitting X-rays with sufficient amplitude and coherence to produce the HFQPOs. In addition, we discuss the important role of the magnetic field in state transition of BHXBs.