Kavli Affiliate: Luis C. Ho
| First 5 Authors: Jie Liao, Ning Chang, Lang Cui, Pengfei Jiang, Didong Mou
| Summary:
Type-C quasi-periodic oscillations (QPOs) in black hole X-ray transients
typically manifest in the low-hard and hard-intermediate states. This study
presents a detailed spectral and temporal analysis of the black hole candidate
Swift J1727.8-1613 using NICER observations from August and September 2023,
with a focus on the first flare period. The time-averaged spectra, along with
the rms and phase-lag spectra of the QPOs, were jointly fitted using the
time-dependent Comptonization model vkompthdk to examine the geometry of the
corona during this flare. The results offer a comprehensive view of how the QPO
and its associated spectral properties evolve over time. Type-C QPOs were
detected, with the centroid frequency increasing from 0.33 Hz to 2.63 Hz, and
the frequency elevated when this outburst entered the flare state. Correlations
between spectral and temporal properties suggest that type-C QPOs are primarily
modulated by Lense-Thirring precession. Leveraging simultaneous radio
observations that indicate discrete jet ejections, we have, for the first time,
proposed a scenario describing the co-evolution of the disk-corona-jet during a
flare (~ 3 days), partially supported by polarization data in soft gamma-ray
band from INTEGRAL/IBIS. A phenomenological analysis of the corona scenario was
also conducted.
| Search Query: ArXiv Query: search_query=au:”Luis C. Ho”&id_list=&start=0&max_results=3