Are low-frequency quasi-periodic oscillations in accretion flows the disk response to jet instability?

Abstract

Low-frequency quasi-periodic oscillations, or LFQPOs, are ubiquitous in black hole X-ray binaries and provide strong constraints on the accretion-ejection processes. Although several models have been proposed, none has been proven to reproduce all observational constraints, and no consensus has emerged so far. We make the conjecture that disks in binaries are threaded by a large-scale vertical magnetic field that splits it into two radial zones. In the inner jet-emitting disk (JED), a near equipartition field allows driving powerful self-collimated jets, while beyond a transition radius, the disk magnetization is too low and a standard accretion disk (SAD) is settled. In a series of papers, this hybrid JED-SAD disk configuration has been shown to successfully reproduce most multiwavelength (radio and X-rays) observations, as well as the concurrence with the LFQPOs for the archetypal source GX 339-4. We first analyze the main QPO scenarios provided in the literature: (1) a specific process occurring at the transition radius, (2) the accretion-ejection instability, and (3) the solid-body Lense-Thirring disk precession. We recall their main assumptions and shed light on some severe theoretical issues that question the capability of reproducing LFQPOs. We then argue that none of these models can be operating under JED-SAD physical conditions. We finally propose an alternative scenario according to which LFQPOs are the disk response to an instability triggered in the jets near a magnetic recollimation zone. This situation can account for most of the type C QPO phenomenology and is consistent with the global behavior of black hole binaries. This nondestructive jet instability remains to be calculated, however. If this instability is numerically confirmed, then it might also naturally account for the jet wobbling phenomenology seen in various accreting sources such as compact objets and young forming stars.

Low-frequency quasi-periodic oscillation in MAXI J1820+070: Revealing distinct Compton and reflection contributions

“…Dauser et al 2013;Kara et al 2016). Other proposals which attribute the broadband X-ray LFQPOs as due to processing jet alone (Ma et al 2020;Ferreira et al 2022) is not supported by our spectral analysis, as a reflection component with strong effect of reflection fraction is required.…”

Quasi-periodic Oscillations in GX 339−4 during the 2021 Outburst Observed with Insight-HXMT

“…However, as indicated by Marcel & Neilsen (2021), this model may not be consistent with the realistic accretion flow properties at all times. A disk-jet scenario under the framework of hybrid disk radial zones is thus proposed to explain the existence of QPOs in X-rays, UV, and IR and successfully matches most of the observed data for GX 339−4 (Ferreira et al 2022).…”

Chasing the Break: Tracing the Full Evolution of a Black Hole X-Ray Binary Jet with Multiwavelength Spectral Modeling

“…The changing frequency of QPOs is closely related to changes in the geometry of the accretion flow, since both the frequency and inner radius of the disk change during the course of an outburst. The origin of LFQPOs is still debated, but it is typically attributed to instabilities in the accretion flow, instabilities in the jet (Ferreira et al 2022), or Lense-Thirring precession of either the inner hot accretion flow present in the hard state (Stella & Vietri 1998;Ingram et al 2009), which is directly related to the Compton tail in the X-ray spectrum, or of a small-scale jet (Ma et al 2021). In J1820 only LFQPOs have been reported throughout the outburst (e.g., Stiele & Kong 2020, with Swift-XRT and NICER data), as shown in Figure 6, top panel.…”