Abstract Details
| Name: Divya Rawat Affiliation: IIT Kanpur Conference ID: ASI2019_122 Title : Study of timing and spectral evolution from χ to heartbeat class in GRS 1915+105 using LAXPC and SXT Authors and Co-Authors : Divya Rawat, Prof. Ranjeev Misra, Prof. J. S. Yadav, Prof. Pankaj Jain Abstract Type : Oral Abstract Category : Stars, ISM and Galaxy Abstract : In this work, we present a ∼90 ks continuous monitoring of the Galactic micro-quasar GRS 1915+105 with AstroSat when the source undergoes a major transition from a non-variable, radio-quiet χ class to a structured, large amplitude, periodic heartbeat state. We show that such transition takes place via an intermediate state when the large-amplitude, irregular variability of the order of hundreds of seconds in the soft X-ray band turned into a 100-150 sec regular, structured, nearly periodic flares similar to ρ class/heartbeat oscillations. We have performed time-resolved spectroscopy on the heartbeat state using simultaneous LAXPC and SXT data covering the broad energy range 0.3-80.0 keV. We have considered the case when the gamma is not varying and have studied the variation of accretion rate, radius and fraction scatter with time. A time lag of <=23.75 secs between the accretion rate and fraction scatter is reported. No time delay between radius and accretion rate is observed. The time lag between the fraction scatters and the accretion rate is maybe the time delay between the seed photons falling from the inner part of the disk and the comptonized photons coming out from the corona. |