Investigation into the diversity of relativistic explosions in the universe

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Gamma-ray bursts (GRBs) are characterized by brief and intense jetted emission of gamma-ray radiation, making them some of the most energetic events in the universe. They last from milliseconds up to over a hundred seconds and are typically followed by afterglows - extended emission in the form of EM radiation from X-ray to radio wavelengths. Afterglows are not tied only to GRBs, but are observed with other energetic explosions as well, or might, theoretically, appear on their own, if the GRB emission did not take place or was impossible to observe.Studying GRBs and their afterglows can provide valuable insight into jet formation and how relativistic explosions evolve in time, as well as provide information on their progenitors, or the resulting nucleosynthesis of heavy elements. However, what is often difficult to measure is how common the different types of relativistic events are, and what are their true occurrence rates.The project at first will be focused on modelling a single afterglow event in multiple wavelengths. However, the overall aim is to investigate a sample of afterglows and set constraints on how variables such as jet opening angle, Lorentz factor or progenitor star metallicity influence the production and observation rate of those events, as well as the rates of different jet phenomena. This will be done through the analysis of observational data from facilities like the Liverpool Telescope (LT), Zwicky Transient Facility (ZTF), or Lick, as well as comparison to numerical simulations.Additionally, if a neutron star merger is detected from gravitational wave observations, then I will take part in searching for its optical counterpart and its analysis. This would help constrain the rate of compact object mergers and provide additional data on the evolution of relativistic explosions.