Abstract Details

Name: Yash Bhargava
Affiliation: IUCAA
Conference ID: ASI2020_289
Title : Shots of Cyg X-1
Authors and Co-Authors : Yash Bhargava, Nandini Hazra, Md Shah Alam, Jayashree Roy, A. R. Rao
Abstract Type : Oral
Abstract Category : Stars, ISM and Galaxy
Abstract : In the presentation, the speaker will talk about the observed sub-second flaring (also known as "shots") in the persistent X-ray binary, Cygnus X-1. The light curve of Cygnus X-1 shows a sudden increase in count rate by a factor of 2-3 for short durations (~1 s). The shots are observed in different energy bands, and different shot profiles are observed across these energies, indicating a change in the spectrum across the shots. We use a 250 ks long AstroSat observation of the source in Hard State to study these enigmatic features. We study the timing and spectral properties of the shots using AstroSat LAXPC in the energy band of 3-80 keV. Comparing the overall spectrum in 0.7-100 keV energy band with the shot-resolved spectrum allowed us to investigate differences between the shot and non-shot segments of the observation. Using the high number of photons collected with the AstroSat-LAXPC, we compare the shot-resolved power density spectrum with the averaged power spectrum to infer the geometry of the source. The speaker will also discuss the mechanism of shot generation inferred from the results.