Abstract Details

Name: Divita Saraogi
Affiliation: IIT Bombay
Conference ID: ASI2021_395
Title : CZTI polarisation study of GRB180427A and GRB180806A
Authors and Co-Authors : Divita Saraogi
Abstract Type :
Abstract Category : Instrumentation and Techniques
Abstract : Polarimetric studies of the prompt emission of gamma ray bursts (GRB) in the Gamma ray and X-ray band are highly prized for testing and constraining various theoretical models of GRBs. Polarization studies are difficult owing to the diversity, variability and brevity of these events as well as the photon hungry nature of the field of high energy polarimetry. As a result, studies carried out in hard X-ray bands till date are inadequate to constrain these models. The CZTI instrument onboard AstroSat is an instrument designed mainly for spectroscopic study of astronomical objects in energy band 20keV to 200keV. The 5mm thick pixelated CZT detectors in this instrument lead to a high probability of Compton scattering and detection of the scattered photon: enabling us to use CZTI as a Compton polarimeter in energy range 100−300keV. The Polarization measurements can be made by measuring azimuthal distribution of simultaneous events in two adjacent pixels. Polarization measurements of several GRBs by CZTI have been reported in literature. Here, we discuss the detailed polarization analysis for two new bursts: GRB180427A and GRB180806A. We find that the bursts do not show any statistically significant polarization, and discuss the implications of this result.