Year: 2026
Type: article
Abstract: MAXI J1348-630, a low-mass black hole X-ray binary, exhibited a major outburst in early 2019 followed by a weaker reflare before returning to quiescence. We analyze Insight-Hard X-ray Modulation Telescope observations of this reflare over MJD 58637–58691 in the 1–100 keV band, together with radio monitoring, to investigate the disk–corona–jet evolution. The X-ray spectral analysis shows that the disk flux and the total coronal-powered flux, defined as the sum of the direct Comptonized continuum and reflected emission, follow a similar rise–plateau–decay pattern, with the latter dominating the X-ray emission. Our interpolated cross-correlation function analysis reveals no robust evidence for a nonzero lag on day timescales between the radio emission and either the X-ray count rates or the decomposed disk and total coronal-powered fluxes. This result is consistent with close coupling among the truncated disk, hot inner flow/corona, and compact jet on day timescales, while minute-to-hour delays remain unresolved. Compared with the ordered multiwavelength evolution observed during the 2019 main outburst, this distinct timing behavior suggests that the reflare is not merely a fainter repetition of the major event, but may instead reflect renewed activity within a residual hard-state–like inner accretion structure, potentially involving a lower-lying or more horizontally extended corona temporally coupled to the compact jet on day timescales.
Source: The Astrophysical Journal
Authors: Xiao Chen, Hanji Wu, Yongjie Jin, Weiping Liu, Wei Wang
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
OpenAlex ID: W7221191720