The discovery of a high-energy astrophysical neutrino flux by IceCube has opened a new observational window on the non-thermal Universe. Recent IceCube results also indicate a Galactic diffuse emission, yet its limited angular resolution makes it difficult to disentangle an extended Galactic background from individual sources. The ANTARES detector, despite its smaller size, provided the first measurements from the Northern Hemisphere and valuable constraints on the diffuse flux. Its successor, KM3NeT-ARCA, offers a major improvement in angular resolution (<0.1° above 100 TeV) and an increased effective area, making it ideally suited to isolate resolvable sources and test production models of high-energy neutrinos.
This PhD project envisions a joint analysis of ANTARES archival data, early KM3NeT data, and potentially IceCube data, leveraging the complementarity between these instruments. The goal is to distinguish the Galactic diffuse emission from identifiable or extended sources (such as supernova remnants, PeVatrons, etc.) through a combined spatial and spectral analysis using template fitting. Advanced likelihood and potentially machine-learning methods will be developed to optimize the astrophysical signal selection and characterize the neutrino sky morphology.
The project will be conducted within the APC laboratory (Astroparticle and Cosmology Laboratory, Paris), an active member of both the ANTARES and KM3NeT collaborations. The team has recognized expertise in multi-messenger astrophysics, combining neutrino data analysis, gamma-ray observations, and phenomenological modeling of cosmic-ray interactions in the Galaxy, in close connection with renowned experts at APC. This environment will enable the implementation of a multi-messenger approach to correlate neutrino observations with gamma-ray data, providing powerful constraints on emission mechanisms.
The expected outcome is to make a step towards resolving the Galactic neutrino sky: distinguishing diffuse emission from discrete sources, testing theoretical models of particle acceleration, and ensuring consistency between IceCube results in the Southern Hemisphere and the new measurements from KM3NeT in the North. Through this synergy, the thesis will contribute to the emergence of a detailed neutrino-based cartography of the Milky Way.