Speaker
Description
4U 1543-47 is a galactic low-mass X-ray binary discovered in 1971. It has undergone five outbursts. The fifth outburst that happened in 2021 marks the source as the brightest X-ray binary source ever reported with a peak X-ray intensity of $\sim$11 Crab in 2-4 keV with MAXI/GSC. We aim for a comprehensive analysis of the wideband spectral characteristics of the source using NICER, NuSTAR and AstroSat Observations. We carried out phenomenological and reflection modelling using simultaneous reflection NICER-NuSTAR and AstroSat epochs. We found that the source was in HSS throughout, with a steep Γ due to a very small fraction (< 3%) of inverse-Comptonized photons. Reflection modelling reveals that the inclination of the system is between $\sim$32°-40°, disk possesses high ionization (log $\xi$ > 3) and overabundance of iron (3.6−10 A$_{Fe \odot}$). We reported the presence of strong and dynamic absorption features in the spectra between $\sim$8-11 keV throughout the outburst. This detection is the first of its kind for X-ray binaries. In addition, there exists a neutral absorption edge feature in the spectrum. We studied the evolution of the equivalent width of both components and found that these components follow the same trend with a delay of typical viscous timescale of 10-15 days. In this presentation, I plan to discuss the physical origin of the observed absorption feature and the accretion dynamics of 4U 1543-47 during the 2021 outburst.
| Presentation Type | Oral |
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