Neutrinos from the cosmic noon: a probe of the cosmic star formation history

Multiple astrophysical probes of the cosmic star formation history (CSFH) indicate a period of peak star formation known as the cosmic noon between 1.5 ≲ z ≲ 3.5. In this work, we explore the potential of future measurements of the diffuse supernova neutrino background (DSNB) at the Hyper-Kamiokande (HK) experiment to be sensitive to variations in the expected star formation rate at cosmic noon. Motivated by a statistically mild discrepancy between Hα and UV/IR probes of the CSFH, which indicate a factor of ∼ 3 difference in the CSFH near the cosmic noon, we construct two benchmark hypotheses based on these different data sets. Since the cosmic noon neutrinos are redshifted to low energies, a low threshold sensitivity of any detector will be critical for discriminating between these benchmark hypotheses. We explore whether HK loaded with Gadolinium, with a positron threshold energy of 10 MeV, would be sensitive to the difference between these two CSFH hypotheses. Assuming that the supernova (SN) neutrino spectrum can be well determined by calibrating core-collapse SNe simulations to observations of nearby SNe, we find that only for very high core-collapse SN temperatures, HK would be sensitive to the difference in the benchmark CSFHs, and even then, over a 10–30 year time scale. Future experiments must lower their thresholds to be more sensitive to cosmic noon neutrinos.