Affiliation: IIT Bombay
Conference ID : ASI2022_331
Title : Daksha: X-ray polarisation sensitivity
Authors : Author: Suman Bala Co-Authors: Parth Sastry, Divita Saraogi, Sujay Mate, Sourav Palit, Varun Bhalerao, Shriharsh Tendulkar, Mithun NPS, CS Vaishnav, Santosh Vadawale
Abstract Type: Poster
Abstract Category : Extragalactic Astronomy
Abstract : The proposed Daksha space telescopes will detect the highest number of GRBs and other high energy transients of any mission to date. In addition to the interesting science with fainter and more distant sources, Daksha will also make a tremendous impact on the study of bright transients by measuring rapid spectral and temporal variations. A key feature is Daksha’s ability to measure X-ray polarisation by utilizing multi-pixel events created by Compton scattering of incoming photons. The basic principles of such polarisation measurement have been demonstrated with AstroSat CZTI. Daksha has two major advantages that will enable more robust polarisation measurements. First, the effective area of Daksha is over an order of magnitude higher than CZTI. Second, the quasi-hemispherical design of the payload ensures different angles of incidence on different detector units, allowing us to quantify and control systematics in the measurement. Given the importance of polarisation measurements in the mission, we plan to extensively validate polarisation measurements with simulations and laboratory experiments. We have undertaken detailed monte-carlo simulations for Daksha polarisation sensitivity using GEANT4. Here we describe our simulations, analysis algorithms, and results. We find that Daksha has higher polarisation sensitivity than any other high energy transients mission.