X-ray spectral and temporal evolution of atoll source 4U 1820-30 with AstroSat: detection of high frequency quasi-periodic oscillation

Subhasish Das, Vivek Kumar Agrawal, Parijat Thakur +4

AstroSat/LAXPC and SXT observed the persistent neutron star low-mass X-ray binary 4U 1820-30 between 2016 and 2022. During these observations, the hardness-intensity diagram (HID)…