| Abstract : | Despite studying the GRB prompt emission for over three decades, the exact nature of the prompt emission mechanism is not yet understood well. Synchrotron radiation from a non-thermal population of ultra-relativistic electrons is expected to be a prime candidate for prompt radiation. However, the observed hard X-ray spectra of the prompt emission are generally found to be harder than that expected from fast cooling Synchrotron radiation. Recent studies for a few GRBs for which the prompt emission observations are available down to soft X-ray band have revealed that an additional low-energy power-law or a thermal component can describe the hardening of the spectrum. However, the number of such GRBs with soft X-ray coverage of prompt emission is very small so far. Further, time-resolved spectral studies of some of the brightest GRBs have shown that the spectral properties of the prompt emission exhibit significant temporal evolution. Thus, it is essential to have wideband spectroscopic observations with sufficient sensitivity, particularly covering the soft X-ray range for a large sample of GRBs, to properly understand the characteristics of the prompt emission. The proposed Indian GRB/EMGW mission, Daksha, with its wide energy range of ~ 1 keV to ~1 MeV and very high sensitivity, can unravel many of the mysteries of GRB prompt emission. Daksha covers the broad energy range using three different detectors: ~1 to ~30 keV Low energy (LE) detector, ~20 to ~200 keV Medium energy (ME) detector, and ~100 keV to ~1 MeV High energy (HE) detector. Here we show the spectroscopic capabilities of all detectors by simulating the expected spectra for typical GRBs in different fluence ranges. |
