| Abstract : | We analyzed the timing and spectral studies of a low mass x-ray binary Neutron star GX 5-1 across the hardness intensity diagram (HID) observed from Astrosat SXT and LAXPC instruments. We performed the Cross-Correlation Function (CCF) studies on GX 5-1 observation data between soft (0.8-2 keV), (3-5 keV ), and hard (10-20 keV), (16-40 keV) energy bands across the HID and found correlated and anticorrelated soft and hard lags. We performed spectral analysis 0.8-20 keV spectra from simultaneous SXT and LAXPC data of HID where lags were noticed. We suggest that the detected lags are readjustment time scales of corona close to the NS and constrained its height to be around a few ten to hundred kms. The detected lags and no significant variation of inner disk front across the HID strongly indicate that structural variation in corona is the most possible cause of Z track in HID. Quasi-Periodic Oscillations with frequencies ranging from 27 to 47 Hz were found in the power density spectra. We found that the centroid frequency changes as the flux changes in single span of observations. In this work we briefly study the caused QPO variation in the context of changes in the Comptonization region. |
