Speaker
Description
Gamma-ray bursts (GRBs) are among the most extreme transients in the universe, but their explosion and emission mechanisms remain unclear. To investigate the nature of GRB jets, we focus on X-ray flares (XFs) and extended emissions (EEs), which are X-ray emissions occurring 100 to 1000 seconds after the main burst. These signals can be observed with recently developed multi-wavelength facilities. In this study, we calculate the associated multi-wavelength emissions from XFs and EEs under the hypothesis that they arise from optically thin synchrotron emission by nonthermal electrons in relativistic jets. By considering ranges of the dissipation radius, $r_{\rm diss}$, and the jet Lorentz factor, $\Gamma$, we determine the parameter space in which detectable emission can be produced at each wavelength. We find that simultaneous ultraviolet and very-high-energy gamma-ray emission associated with XFs or EEs can be detected by Swift/UVOT, SVOM/VT, and CTAO approximately once every three years. The detection and non-detection rates for each detector provide key constraints on uncertain but essential parameters for understanding the physics of GRB jets.
