The 2:3:6 QPO structure in GRS 1915+105 and cubic subharmonics in the context of relativistic diskoseismology

TL;DR

This paper introduces a simple model explaining the 2:3:6 QPO frequency structure in GRS 1915+105 and similar sources, based on diskoseismology and subharmonic resonances, predicting new observable QPOs.

Contribution

The paper presents a novel toy model linking QPO structures to resonances between g-modes and p-waves in accretion disks, advancing understanding of high-frequency QPOs.

Findings

Predicts a QPO at twice the higher twin frequency in twin peak sources.

Suggests the observed 2:3:6 structure results from diskoseismic resonances.

Indicates potential observation of a high-quality factor QPO in GRS 1915+105.

Abstract

We propose a simple toy model to explain the 2:3:6 QPO structure in GRS 1915+105 and, more generally, the 2:3 QPO structure in XTE J1550-564, GRO J1655-40, and H 1743-322. The model exploits the onset of subharmonics in the context of diskoseismology. We suggest that the observed frequencies may be the consequence of a resonance between a fundamental g-mode and an unobservable p-wave. The results include the prediction that, as better data become available, a QPO with a frequency of twice the higher twin frequency and a large quality factor will be observed in twin peak sources, as it might already have been observed in the especially active GRS 1915+105.