A unified accretion-ejection paradigm for black hole X-ray binaries

Abstract

The spectral evolution of transient X-ray binaries can be reproduced by an interplay between two flows separated at a transition radius RJ: a standard accretion disk (SAD) in the outer parts beyond RJ and a jet-emitting disk (JED) in the inner parts. In the previous papers in this series we successfully recover the spectral evolution in both X-rays and radio for four outbursts of GX 339-4 by playing independently with the two parameters: RJ and the disk accretion rate Ṁin. In this paper we compare the temporal evolution of both RJ and Ṁin for the four outbursts. We show that despite the undeniable differences between the time evolution of each outburst, a unique pattern in the Ṁin−RJ plane seems to be followed by all cycles within the JED-SAD model. We call this pattern a fingerprint, and show that even the “failed” outburst considered follows it. We also compute the radiative efficiency in X-rays during the cycles and consider its impact on the radio–X-ray correlation. Within the JED-SAD paradigm, we find that the accretion flow is always radiatively efficient in the hard states, with between 15% and 40% of the accretion power being radiated away at any given time. Moreover, we show that the radiative efficiency evolves with the accretion rate because of key changes in the JED thermal structure. These changes give birth to two different regimes with different radiative efficiencies: the thick disk and the slim disk. While the existence of these two regimes is intrinsically linked to the JED-SAD model, we show direct observational evidence of the presence of two different regimes using the evolution of the X-ray power-law spectral index, a model-independent estimate. We then argue that these two regimes could be the origin of the gap in X-ray luminosity in the hard state, the wiggles, and different slopes seen in the radio–X-ray correlation, and even the existence of outliers.

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

“…Hereafter, we focus on such a framework, the hybrid disk configuration proposed by Ferreira et al (2006b), which has recently been successfully compared to observations in a series of papers (Marcel et al 2018a(Marcel et al ,b, 2019(Marcel et al , 2020(Marcel et al , 2022Ursini et al 2020;Marino et al 2021;Barnier et al 2022). In this framework, a large-scale vertical magnetic field B z is assumed to thread the inner disk regions, for instance, below 10 4 r g , where r g = GM/c 2 is the gravitational radius.…”

Extended Corona Models of X-ray Reverberation in the AGN 1H~0707-495 and IRAS 13224-3809

“…Whilst this is consistent with the findings of Szanecki et al (2020), it is in contrast to their findings that the source is compact within a few gravitational radii (when modelled using the relativistically smeared reflection from the accretion disc). Variations of the inner regions and accretion flow have been explained via transitions between the jet emitting disc (JED) and standard accretion disc (SAD) framework (Marcel et al 2022) and the framework of coupled hot accretion and jet model for GBHBs and AGN (Yang et al 2015), suggesting that a two-phase accretion flow could be driving the observed variability. For 1H 0707-495, the profile of Γ is flat at lower luminosity before showing a mild positive correlation at 10 −1.7 𝐿/𝐿 Edd 10 −1.5 (Figure 9).…”

The 2022 Outburst of IGR J17091–3624: Connecting the Exotic GRS 1915+105 to Standard Black Hole X-Ray Binaries

“…In summary, our data suggest that IGR J17091-3624 in its 2022 outburst reached a relatively high Eddington ratio because of the L-T relation in the SIMS. Depending on the accretion disk model, this can be, e.g., 30% L Edd (Abramowicz et al 2010), but depends on several parameters, such as the magnetization (e.g., Marcel et al 2022). We cannot rule out the possibility that IGR J17091-3624 reached a super-Eddington luminosity based on the available black hole mass and distance constraints.…”