Fisher, Lalenthra2024-01-262024-01-262024https://hdl.handle.net/10539/37435A research report submitted in fulfilment of the requirements for the degree of Master of Science to the Faculty of Science, School of Physics, University of the Witwatersrand, Johannesburg, 2023Context: The first extra-galactic gamma-ray binary, LMC P3, is a gammaray binary comprising of an unconfirmed compact object and an O-star and is located in the Large Magellanic Cloud. Initially discovered in Fermi-LAT data, it shows an orbital period of 10.3 days. H.E.S.S. has reported the detected Very High Energy (VHE) gamma-ray emission during only 20% of the orbit (Abdalla et al. 2018), between orbital phases 0.2 and 0.4, which roughly corresponds to the inferior conjunction of the compact object. Purpose: H.E.S.S. has continued the observations of this object since then. This work aims to produce a data analysis with a much deeper data set. The new data allowed for a more precise measurement of the location of the VHE gamma-ray peak along the orbit of the system to be made. Methods: Using LMC observations from the HESS array from 2003- 2022, a spectral and temporal analysis was conducted using the analysis package Gammapy. N 157B is used as a standard candle for a consistency check. The analysis incorporates the latest orbital solutions for the system. Results: The peak of the VHE emission was found at a phase 0.268 - 0.366, which with the current orbital solution, places this after inferior conjunction. Conclusions: The VHE light curve is better constrained w.r.t. the previous H.E.S.S. publication(Abdalla et al. 2018). The peak of emission is reduced from 20% to just under 10% of the orbital period. In-depth physical modelling is required to explain the physical origin of the VHE gamma-ray emission.enGammaray binaryLarge magellanic cloudDissertation