Detection of a non-harmonic QPO precursor to Type-B in the HIMS of MAXI J1820+070 using NICER timing data.
The ABC of low-frequency quasi-periodic oscillations in Black-Hole Candidates: analogies with Z-sources
4 Pith papers cite this work. Polarity classification is still indexing.
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Pith papers citing it
abstract
Three main types of low-frequency quasi-periodic oscillations (LFQPOs) have been observed in Black Hole Candidates. We re-analyzed RXTE data of the bright systems XTE J1859+226, XTE J1550-564 and GX 339-4, which show all three of them. We review the main properties of these LFQPOs and show that they follow a well-defined correlation in a fractional rms vs. softness diagram. We show that the frequency behavior through this correlation presents clear analogies with that of Horizontal-, Normal- and Flaring-Branch Oscillations in Z sources, with the inverse of the fractional rms being the equivalent of the curvilinear coordinate Sz through the Z track.
fields
astro-ph.HE 4years
2026 4representative citing papers
X-ray emission lines and a broad iron feature emerged in changing-look AGN 1ES 1927+654 concurrently with radio-jet formation and declining ionized outflows from 2022 to 2025.
Detection of an imaginary QPO in AT2019wey whose frequency drops from ~5 Hz to ~1 Hz with rising phase lags as the source transitions through HIMS and LHS, showing U-shaped phase-lag spectrum in HIMS.
Comprehensive analysis of AstroSat data shows a sign change in QPO time lags at ~2 Hz for high-inclination sources, consistent with a transition from elongated jet-like to compact corona.
citing papers explorer
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Discovery of a quasi-periodic oscillation non-harmonically related to the Type-C QPO in the hard intermedidate state of MAXI J1820+070
Detection of a non-harmonic QPO precursor to Type-B in the HIMS of MAXI J1820+070 using NICER timing data.
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The emergence of X-ray emission lines during relativistic radio-jet formation in the changing-look active galactic nucleus 1ES 1927+654
X-ray emission lines and a broad iron feature emerged in changing-look AGN 1ES 1927+654 concurrently with radio-jet formation and declining ionized outflows from 2022 to 2025.
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An atypical X-ray variability component in the black hole candidate AT2019wey
Detection of an imaginary QPO in AT2019wey whose frequency drops from ~5 Hz to ~1 Hz with rising phase lags as the source transitions through HIMS and LHS, showing U-shaped phase-lag spectrum in HIMS.
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Understanding corona and disk evolution in black hole X-ray binaries through a comprehensive study of their broadband variability and QPO characteristics
Comprehensive analysis of AstroSat data shows a sign change in QPO time lags at ~2 Hz for high-inclination sources, consistent with a transition from elongated jet-like to compact corona.