2023MNRAS.519L..32T

We infer the expected detection number of pair instability supernovae (PISNe) during the operation of the Euclid space telescope based on binary population models. Our models reproduce the global maximum at the primary BH mass of ∼9-10 M_⊙ and the overall gradient of the primary BH mass distribution in the binary BH merger rate consistent with recent observations. We consider different PISN conditions depending on the ¹²C(α, γ)¹⁶O reaction rate. The fiducial and 3σ models adopt the standard and 3σ smaller reaction rates, respectively. Our fiducial model predicts that Euclid detects several hydrogen-poor PISNe. For the 3σ model, detection of ∼1 hydrogen-poor PISN by Euclid is expected if the stellar mass distribution extends to M_max = 600 M_⊙, but the expected number becomes significantly smaller if M_max = 300 M_⊙. We may be able to distinguish the fiducial and 3σ models by the observed PISN rate. This will help us to constrain the origin of binary BHs and the reaction rate, although there remains a degeneracy between M_max and the reaction rate. PISN ejecta mass estimates from light curves and spectra obtained by follow-up observations would be important to disentangle the degeneracy.