Speaker
Description
In March 2023, a gamma-ray burst known as GRB 230307A was observed. Recent studies suggest that this event was not a typical burst, but a kilonova — the aftermath of merging neutron stars that create some of the heaviest elements in the Universe. In this talk, I will explore what makes this event unique: its likely host galaxy, and the surprising fact that the explosion occurred more than 40 kpc away from it. I will discuss in particular a detailed modeling of such large offset. Reconciling the observations with theoretical models and simulations requires some fine-tuning, raising questions about how such systems form and evolve. No gravitational waves were detected in this case, but studying GRB 230307A helps us better understand kilonovae as a population and prepares us for what we may learn with the next generation of gravitational-wave observatories. This presentation is based on 2512.09036 (ApJL accepted).