Conveners
Timing properties (Observations, modelling)
- Luciano Burderi (University of Cagliari)
Timing properties (Observations, modelling)
- Phil Uttley (University of Amsterdam)
Timing properties (Observations, modelling): Flash Talk
- Phil Uttley (University of Amsterdam)
The power of timing is that it can strongly constrain source geometry and causal mechanisms. I will review how multi-wavelength timing - from radio to X-rays and beyond - reveals the structure and scales of microquasars and the causal interplay of accreting components on a variety of physical scales. I will survey some lessons learnt from campaigns over past six decades of timing, and then...
In the last 8 years, NICER and Insight-HXMT have opened up new windows to study X-ray variability from the softest to hardest X-rays. With a focus on insights from these instruments, I will review our current understanding of the origin of the rapid (minutes to milliseconds) X-ray variability in black hole X-ray binaries and how we can model the Fourier properties of the variability, to learn...
Fast multi-wavelength studies of black hole transients are revealing a complex and rich phenomenology, opening a new era in the study of disc-jet coupling. In this talk, I will show the latest results regarding an X-ray/Optical and infrared (O-IR) campaign on the bright transient Swift J1727.8-1613. By following the source with NICER, Ultracam HAWKI, and HIPERCAM, for the first time, we were...
It is widely accepted that Type-B quasi-periodic oscillations (QPOs) are causally connected to discrete ejections of relativistic jets in black hole X-ray binaries. Here, I present new results from a bright flare of Swift J1727.8−1613, during which the source evolved from the hard intermediate state (HIMS) into the soft intermediate state (SIMS) and almost immediately back to the HIMS, without...
Black hole X-ray binaries (BHXBs) are key laboratories for studying accretion physics, relativistic jets, and strong gravity. Since its launch in 2017, NASA’s Neutron Star Interior Composition Explorer (NICER) has provided unprecedented X-ray timing and spectral data, enabling new insights into accretion phenomenology and the physics behind. In this talk, I will review what we have learned...
In recent years, fast optical-infrared (O-IR) variability of LMXBs has opened a new window in the study of the jet and accretion flow properties. All objects observed thus far are known to have an intermediate-high inclination, biasing our interpretations and hampering the possibility of adequately testing models. Here, I present the first sub-second multiwavelength analysis of low inclination...
Low-frequency quasi-periodic oscillations (LFQPOs) are among the most striking timing features in black hole X-ray binaries, yet their physical origin and diversity remain unresolved. In this talk, I will present a new framework that naturally explains the transition from type C to type B QPOs through the progressive warping of the accretion disk. I will show that when the transition radius of...
Based on the AGNSED model (Kubota & Done 2018), we developed a spectral model, SSsed, which describes the disc–corona geometry in stellar-mass black hole binaries. We applied this model to RXTE spectral datasets of XTE J1550–564 and compared the estimated coronal radii
$R_{\rm cor}$ with independently determined centroid frequencies of low-frequency QPOs in their power density spectra. In...
Black hole X-ray binaries (BHXBs) show strong variability in their X-ray light curves over a broad range of time scales. Fast X-ray variability in BHXBs is key to understanding the properties of the innermost regions of the accretion flow in these sources. Among the most notable features of this variability are quasi-periodic oscillations (QPOs), which provide a unique insight due to their...
The study of fast variability properties in X-ray binaries advances our understanding of the properties of the accretion flow around the compact object. As most timing studies focus on the power spectrum (PS), the phenomenology of the cross spectrum (CS), especially the coherence, is less understood. In this talk, I will present the results of a systematic study of the evolution of both PS...
Recent timing studies of black hole X-ray binaries have revealed a narrow drop in the coherence between soft (<2 keV) and hard (>2 keV) bands in the 1–5 Hz range during soft-to-hard transitions in outburst decay, at lower luminosities than the hard-to-soft transitions observed during outburst rise. A sudden jump in the phase lags accompanies this coherence drop at the same frequency. Using a...
X-ray binaries (XRBs) are systems containing accreting black holes and neutron stars that launch relativistic jets. Recently, it has been shown that we can move beyond spectral and imaging studies and use time-domain observations to measure fundamental properties of the jets and accretion flow, and in turn, begin to address key open questions in compact object research. However, XRB timing...
Spectral-timing analyses are a key tool to investigate the innermost region in accreting X-ray sources.
However, when encounter them, such techniques can appear strenuous to implement and use in an easy way. An advantageous way is to rely on well-maintained and reliable software such as Stingray.
Stingray is an open-source Python library that is able to compute the main Fourier analyses...
We present a comprehensive spectral and timing analysis of the newly discovered black hole transient Swift J1727.8--1613, based on broadband (2--150 keV) observations from Insight-HXMT during its 2023 outburst. Using the flexible, energy-conserving SSsed model, we identify the presence of both thermal and non-thermal Comptonization components in the hard component dominated state. We track the...
The energy-dependent variability of black hole X-ray binaries (BHXRBs) provide crucial insights into the physical processes at play in the accretion flow of these systems. We analyze the rapid X-ray variability of the BHXRB Swift J1727.8-1613 during its 2023 outburst, using observations from the Hard X-ray Modulation Telescope. We detect, for the first time, a dip-like feature in the Real part...
The timing analysis of X-ray binaries (XBs) is crucial for understanding the structure and dynamics governing these systems. Since the memorable 2023 outburst of the Low-Mass X-ray binary Swift J1727.8–1613, observations have been conducted across the entire electromagnetic spectrum, progressively constraining the source parameters. Here, we present the first XMM-Newton timing analysis of...
Black hole low-mass X-ray binary (BH-LMXB) systems are exceptional laboratories for studying accretion physics under strong gravity. The variability of these systems, characterised by the power spectra changes systematically in different states. The power color analysis offers a robust way of classifying the spectral states, as an alternative to the traditional HID (Hardness-intensity diagram)...
