Young and massive star clusters have been proposed as potential sources of cosmic rays reaching PeV energies, offering a complementary perspective to the supernova remnant scenario. The collective action of stellar winds in a compact cluster creates a strong wind termination shock, which may accelerate particles efficiently over million-year timescales. Supernova remnants within the cluster cores contribute an additional, eventually dominant, energy source. The subsequent hadronic interactions of these accelerated particles produce gamma rays and neutrinos. Using a model that accounts for both wind termination shock and supernova remnant contributions, we calculate the expected flux of secondary particles from the local star clusters identified by the Gaia satellite. We assess their detectability with current and next-generation observatories, including CTAO, LHAASO, and KM3NeT, employing detailed sensitivity curves for extended sources.
Celli et al. (Tue,) studied this question.