REVIEW 2 cited by
Discovery of oscillations above 200 keV in a black hole X-ray binary with Insight-HXMT
Not yet reviewed by Pith; the record is open.
This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.
SPECIMEN: schema-true, not a live event
T0 review · schema-true
One-sentence machine reading of the paper's core claim.
pith:XXXXXXXX · record.json · timestamp
read the original abstract
Low-frequency quasi-periodic oscillations (LFQPOs) are commonly found in black hole X-ray binaries, and their origin is still under debate. The properties of LFQPOs at high energies (above 30 keV) are closely related to the nature of the accretion flow in the innermost regions, and thus play a crucial role in critically testing various theoretical models. The Hard X-ray Modulation Telescope (Insight-HXMT) is capable of detecting emissions above 30 keV, and is therefore an ideal instrument to do so. Here we report the discovery of LFQPOs above 200 keV in the new black hole MAXI J1820+070 in the X-ray hard state, which allows us to understand the behaviours of LFQPOs at hundreds of kiloelectronvolts. The phase lag of the LFQPO is constant around zero below 30 keV, and becomes a soft lag (that is, the high-energy photons arrive first) above 30 keV. The soft lag gradually increases with energy and reaches ~0.9s in the 150-200 keV band. The detection at energies above 200 keV, the large soft lag and the energy-related behaviors of the LFQPO pose a great challenge for most currently existing models, but suggest that the LFQPO probably originates from the precession of a small-scale jet.
Forward citations
Cited by 2 Pith papers
-
Energy-dependent Optical/Near-infrared and X-ray Correlations in Swift J1727.8-1613
For Swift J1727.8–1613, the optical–X-ray correlation flips sign with X-ray energy, and the QPO lag is flat (~60–80 ms) from 2 to 150 keV.
-
Spectro-temporal Investigation of Quasi-periodic Oscillations From Black Hole X-ray Binary 4U 1630-472 Using $\textit{NICER}$
Type-C QPOs in the 2021 outburst of 4U 1630-472 show a strong photon index versus frequency correlation and a significant Q-factor break at about 2.31 Hz.
Discussion (0). Continue with ORCID to comment.