Tracing the Accretion Geometry of H1743-322 with Type C Quasiperiodic Oscillations in Multiple Outbursts

Abstract

We present a systematic analysis of type C quasiperiodic oscillation (QPO) observations of H1743-322 throughout the Rossi X-ray Timing Explorer era. We find that, while different outbursts have significant flux differences, they show consistent positive correlations between the QPO fractional rms amplitude and nonthermal fraction of the emission, which indicate an independence of the intrinsic QPO rms on individual outburst brightnesses in H1743-322. However, the dependence of the QPO rms on frequency is different between the outburst rise and decay phases, where the QPO fractional rms of the decay phase is significantly lower than that of the rise phase at low frequencies. The spectral analysis also reveals different ranges of coronal temperature between the two outburst stages. A semiquantitative analysis shows that the Lense–Thirring precession model could be responsible for the QPO rms differences, requiring a variable coronal geometric shape. However, the variable-Comptonization model could also account for the findings. The fact that the rms differences and the hysteresis traces in the hardness–intensity diagram accompany each other indicates a connection between the two phenomena. By correlating the findings with QPO phase lags and the quasi-simultaneous radio flux previously published, we propose there could be corona-jet transitions in H1743-322 similar to those that have been recently reported in GRS 1915+105.

A Phase-resolved View of the Low-frequency Quasiperiodic Oscillations from the Black Hole Binary MAXI J1820+070

“…If the QPOs are produced by the corona's L-T precession, the X-ray QPO variability is due to the geometric wobble of the corona, which changes the projection area of the corona with respect to the observer to modulate the observed X-ray flux (Ingram et al 2009;You et al 2018You et al , 2020Shui et al 2023).…”

“…Since the geometric shape of a corona might not be a sphere (e.g., a crushed sphere, Ingram & Done 2012;Shui et al 2023), the optical depth of the corona with respect to the observer could vary over the precession period. The illuminating continuum in relxillCp is nthComp (Życki et al 1999), wherein the spectral shape is determined by the combination of the electron temperature (kT e ) and the optical depth (τ).…”

“…However, the optical depth of the corona modulates in the opposite manner due to the self-occultation effect (You et al 2018). Quantitatively, according to simplified calculations by Shui et al (2023), if the corona's shape resembles a crushed sphere, there might exist an anticorrelation between the flux and the corona's optical depth. Equation (9) of Shui et al (2023) describes the modulation of the corona's optical depth as the corona precesses:…”

Recovery of High-energy Low-frequency Quasiperiodic Oscillations from Black Hole X-Ray Binary MAXI J1535–571 with a Hilbert–Huang Transform Method

“…Previous studies commonly combined multiple observations to enhance the S/N of QPO peaks in the PDS (see, e.g., Ma et al 2021;Yang et al 2022). However, this approach assumes similar QPO frequencies across the combined observations, which is not typically the case during the HIMS of outburst rising phase of BHXRBs, where the QPO frequency tends to increase rapidly (see, e.g., Huang et al 2018;Shui et al 2021Shui et al , 2023a. If the QPO frequencies among combined observations show significant differences, multiple fundamental QPO peaks would appear in the long-term combined PDS in the low-energy band (see Figure 4).…”

“…While it has now become standard practice to fit power spectra in X-ray binaries with a combination of both broad and peaked components modeled as Lorentzians (see, e.g., Belloni et al 2002;Yang et al 2022;Zhou et al 2022;Shui et al 2023a), there is currently no physical backing behind the use of Lorentzian components. Additionally, we find the continuum of the power spectrum from obsID P011453500201 in 30-120 keV can be well-fitted with a broken power-law function (see Figure 7).…”