Daksha: On Alert for High Energy Transients

The discovery of gravitational waves from a binary neutron star merger, along with radiation across the electromagnetic spectrum, was a hallmark event in astrophysics. This was also the first confirmed detection of high energy radiation from far off-axis directions for a short gamma-ray burst: and it was discovered that the emission was extremely faint. As the sensitivity of the GW detector network increases and more distant event are discovered, the current global network of high energy satellites will fall short in terms of sensitivity as well as coverage. To address this problem, we present Daksha: a pair of satellites that will provide continuous coverage of the entire sky with an order of magnitude higher sensitivity than existing satellites. Daksha satellites use three types of detectors with overlapping energy ranges to attain high sensitivity from 1 keV to 1 MeV. Daksha will provide burst alerts within minutes, with an on-board localisation to ~10 degrees. Ground processing will be used to improve localisation, spectra, and search for hard X-ray polarisation. Daksha will also be the only mission to obtain soft X-ray spectra of prompt emission from high energy transients including GRBs. Daksha has been recommended as one of the leading space astronomy missions in India to be taken up for further study for realisation in a few years time. Seed funding has been provided to demonstrate a proof-of-concept. I will talk about the key science goals of Daksha, discuss its technical specifications and capabilities. I will conclude with mission status and updates.