Speaker
Description
Short gamma-ray bursts (sGRBs) are produced during the merger of compact-object binaries, launching collimated ultrarelativistic jets that generate prompt gamma-ray emission. These events are also expected to produce an approximately isotropic infrared/optical signal rich in lanthanides, known as a kilonova. To date, only a few sGRBs have been associated with kilonova emission, primarily due to limited instrumental sensitivity and incomplete follow-up observations. Recent studies have proposed a mechanism that can shed light on kilonova observational signatures through the interaction of kilonova photons with relativistic electrons within the jet, up-scattering them to higher energies via inverse Compton processes. This mechanism provides a potential pathway for detecting kilonova-related emission at very-high-energy gamma rays within the first two days following the prompt phase. In this work, we search for such high-energy photons using data from the High Altitude Water Cherenkov (HAWC) Observatory. We identify candidate events exhibiting signatures consistent with this process and explore the physical conditions under which inverse Compton up-scattering of kilonova photons may occur in selected sGRB candidates and provide flux upper limits for the other bursts in our sample.