Projects

Research projects with Daksha

The Daksha team welcomes participation from the scientific community in a variety of projects related to Daksha. Here we list a few representative collaboration opportunities. The details for a few of them are listed below. More topics and details will be added to this page from time to time.

Soft X-ray GRB spectroscopy

Overview

Gamma Ray Bursts (GRBs) have conventionally been studied in the hard X-ray and Gamma-Ray bands. Soft X-ray observations typically enter the picture only when studying afterglows. Some progress has recently been made in the soft X-ray prompt spectroscopy with data from Einstein Probe – but the overall soft X-ray spectra of GRBs remain poorly studied and understood.

Broadband spectra of GRBs are typically modelled with a phenomenological Band function or a synchrotron-like cutoff powerlaw. In both cases, a spectral peak or a break is predicted at high energies (hundreds of keV or higher). A disagreement exists between the observed prompt spectral shape and the theoretical synchrotron predictions from a non-thermal population of ultra relativistic electrons in the soft X-ray band. Studies of long GRB spectra by Oganesyan et al (2017) showed the presence of low energy breaks (~2 – 30 keV) as well. What is the cause of these soft breaks? Can they be modelled by marginally fast cooling in synchrotron regime? Or are they related to thermal emission?

There is no strong evidence for such soft spectral breaks in short GRBs. Is this a real physical effect, potentially related to their intrinsically harder spectra? Or is it just an observational bias resulting from the fewer number of photons in typical short GRBs? 

Goals

The goals of this project are:

References

Time-resolved GRB spectroscopy

Overview

Time-resolved prompt emission studies in Gamma-Ray Bursts (GRBs) reveal two critical unresolved patterns in spectral evolution. First, the spectral evolution from hard to soft energies suggests a complex emission mechanism: initial black body radiation from collapsing material transforms into non-thermal photons through internal shock interactions. Second, the correlation between luminosity and temperature indicates energy dissipation in Poynting flux-dominant outflows, with radiation primarily produced above the photosphere.

For short GRBs, critical open questions remain about the jet's propagation through merger ejecta. The cocoon formation and shock break-out process—characterized by a hard initial spike followed by a soft tail—provides a potential window into understanding neutron star merger dynamics. Crucial uncertainties persist about how the luminosity, duration, and spectral characteristics of these emissions relate to ejecta structure, jet properties, and potentially even the neutron star equation of state.

The fundamental scientific challenge is developing a unified physical model that can explain these complex emission mechanisms. Detailed, millisecond time-resolved spectroscopy across broad energy ranges—as enabled by missions like Daksha with micro-second resolution—represents the most promising path to resolving these outstanding questions in high-energy astrophysics.

Goals

The goals of this project are:

References

Broadband spectroscopy of GRBs

Overview

GRB observations have typically been limited to the hard X-ray and Gamma ray regime, with very few observations of soft prompt emission from GRBs. Consequently, most theoretical GRB models also focus on only the high energy spectra. 

Many interesting questions about GRB physics will become accessible with the availability of broadband spectra Are there unique soft spectral signatures in GRBs? Do the soft and hard spectra arise from the same physical process, or different ones? Are these processes occurring in the same physical region, or are there different emission zones (for instance, photosphere and jet) giving rise to different emission components? How are these components related to each other? How are they expected to evolve with time?

Daksha, with its broadband spectral response, can obtain spectra of GRBs from 1 keV to beyond 1 MeV. The full utilisation of this rich data set is contingent upon having detailed spectroscopic models for GRB prompt emission. 

Goals

The goals of this project are:

References