Detectability of Late-time Supernova Neutrinos with Fallback Accretion onto Protoneutron star

Understand

We investigate the late-time neutrino emission powered by fallback mass accretion onto proto-neutron star (PNS), using neutrino radiation-hydrodynamic simulations with full Boltzmann neutrino transport.

• We follow the time evolution of accretion flow onto PNS until the system reaches a steady state.
• A standing shock wave is commonly formed in the accretion flow, whereas the shock radius varies depending on mass accretion rate and PNS mass.
• A sharp increase in temperature emerges in the vicinity of PNS ($\sim 10$ km), which characterizes neutrino emission.