  A comprehensive framework is proposed for the diffuse neutrino fluxes
attributed to two different physical processes in core collapse of massive
stars. In this scheme, models of thermal MeV-scale neutrinos produced at the
core of collapsing stars and non-thermal high-energy neutrinos emitted from
accelerated cosmic rays interacting with circumstellar material are bridged
through features of core-collapse supernovae (progenitor mass and optical
properties). The calculated diffuse fluxes are presented with discussion about
their detection prospects at neutrino telescopes.
