2025ApJ...982...93S

A novel approach is proposed to reveal a secret birth of enhanced circumstellar material (CSM) surrounding a collapsing massive star using neutrinos as a unique probe. In this scheme, nonthermal TeV-scale neutrinos produced in ejecta-CSM interactions are tied with thermal MeV neutrinos emitted from a pre-explosion burning process, based on a scenario that CSM had been formed via the presupernova activity. Taking a representative model of the presupernova neutrinos, the spectrum and light curve of the corresponding high-energy CSM neutrinos are calculated at multiple mass-loss efficiencies, which are considered as a systematic uncertainty. In addition, as a part of the method demonstration, the detected event rates along time at JUNO and IceCube, as representative detectors, are estimated for the presupernova and CSM neutrinos, respectively, and are compared with the expected background rate at each detector. The presented method is found to be reasonably applicable for the range up to ∼1 kpc and even farther with future experimental efforts. The potentialities of other neutrino detectors, such as SK-Gd, Hyper-Kamiokande, and KM3NeT, are also discussed. This is a pioneering work of performing astrophysics with neutrinos from diverse energy regimes, initiating multienergy neutrino astronomy in the forthcoming era where next-generation large-scale neutrino telescopes are operating.