Abstract Details

Name: Unnati Kashyap
Affiliation: IIT Indore
Conference ID: ASI2020_523
Title : Broadband Spectro-timing Analysis of Neutron Star LMXB 4U 1724-30 Using Astrosat.
Authors and Co-Authors : Ms. Unnati Kashyap, Dr. Manoneeta Chakraborty, Prof. Sudip Bhattacharyya.
Abstract Type : Poster
Abstract Category : Stars, ISM and Galaxy
Abstract : Compact objects in X-ray binaries exhibit a plethora of interesting observational features like outbursts, bursts, quasi periodic oscillations (QPOs) and jets that can address the physics of accretion dynamics, strong gravity and ultra-dense degenerate matter. Broadband and spectro-timing studies of compact objects in Low mass X-ray binaries (LMXBs) can put unique constraints on the evolution of the binary components during an outburst phase manifesting as spectral state evolution) and thereby unveiling underlying physical mechanisms. We report the analysis of broadband observation of the poorly studied accreting neutron star LMXB 4U 1724-30 jointly by SXT and LAXPC instruments on board AstroSat. The source was observed by Astrosat in 2017 which corresponded to the low-luminosity non-thermally dominated (hard/island) state of the source over 4 epochs. All of the X-ray broadband spectra can be modeled by a combination of a thermal emission from the accretion disk and a non-thermal emission possibly originating from Inverse comptonization of seed photons from disk. The timing variabilites were also investigated to probe the origin of disk and coronal fluctuations and their dependence on mass accretion. The spectro-temporal analysis and time lag properties of the broadband emission was carried out to derive information about the complete radiative emis- sion behavior and its evolution. The time resolved spectroscopy of of a thermonuclear burst detected during the last observation was performed and the correlation of the burst property on the spectral state was investigated. This unprecedented broadband study will be instrumental to understand the nature of physical processes occurring in the accretion flow as well as corona.