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Main Authors: Ram, Biki, Chakraborty, Manoneeta, Kashyap, Unnati
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2407.15618
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author Ram, Biki
Chakraborty, Manoneeta
Kashyap, Unnati
author_facet Ram, Biki
Chakraborty, Manoneeta
Kashyap, Unnati
contents We report a detailed spectro-temporal analysis of the black hole (BH) low mass X-ray binary (LMXB) 4U 1543-475 during its 2021 outburst using the data from LAXPC (Large Area X-ray Proportional Counters) and SXT (Soft X-ray Telescope) instrument on board AstroSat. We investigate the energy and frequency dependency of the source variability to probe the origin of the disc/coronal fluctuations. Following the state transition (from soft to intermediate state), the emergence of a band-limited noise (BLN) component is observed along with the power law noise (PLN) when the disk is recovering from a sudden decrease in the inner disk radius. A possible correlation between the low-frequency variability amplitude (RMS) and the covering fraction of the non-thermal component is detected. During the final AstroSat observation, a flip-flop phenomenon is reported, where rapid variation in RMS occurs in concurrence with sudden flux transition. An indication of the evolution of inner disk temperature along with a significant change in thermal flux was observed during the flip-flop phase, arguing for a disk instability-driven origin for this phenomenon. Our results suggest that the long-term variability evolution is primarily affected by the coronal changes, whereas the disk behavior governs the short-term variability evolution.
format Preprint
id arxiv_https___arxiv_org_abs_2407_15618
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Spectro-temporal investigation of the black hole X-ray transient 4U 1543-475 during the 2021 outburst
Ram, Biki
Chakraborty, Manoneeta
Kashyap, Unnati
High Energy Astrophysical Phenomena
We report a detailed spectro-temporal analysis of the black hole (BH) low mass X-ray binary (LMXB) 4U 1543-475 during its 2021 outburst using the data from LAXPC (Large Area X-ray Proportional Counters) and SXT (Soft X-ray Telescope) instrument on board AstroSat. We investigate the energy and frequency dependency of the source variability to probe the origin of the disc/coronal fluctuations. Following the state transition (from soft to intermediate state), the emergence of a band-limited noise (BLN) component is observed along with the power law noise (PLN) when the disk is recovering from a sudden decrease in the inner disk radius. A possible correlation between the low-frequency variability amplitude (RMS) and the covering fraction of the non-thermal component is detected. During the final AstroSat observation, a flip-flop phenomenon is reported, where rapid variation in RMS occurs in concurrence with sudden flux transition. An indication of the evolution of inner disk temperature along with a significant change in thermal flux was observed during the flip-flop phase, arguing for a disk instability-driven origin for this phenomenon. Our results suggest that the long-term variability evolution is primarily affected by the coronal changes, whereas the disk behavior governs the short-term variability evolution.
title Spectro-temporal investigation of the black hole X-ray transient 4U 1543-475 during the 2021 outburst
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2407.15618