Developing an end-to-end simulation framework of supernova neutrino detection

Massive stars can explode as supernovae at the end of their life cycle, releasing neutrinos whose total energy reaches 1053, erg. Moreover, neutrinos play key roles in supernovae, heating and reviving the shock wave as well as cooling the resulting proto-neutron star. Therefore, neutrino detectors are waiting to observe the next galactic supernova, and several theoretical simulations of supernova neutrinos are underway. While these simulations concentrate mainly on only the first second after the supernova bounce, the only observation of a supernova with neutrinos, SN 1987A, revealed that neutrino emission lasts for more than 10 seconds. For this reason, long-time simulation and analysis tools are needed to compare theories with the next observation. Our study develops an integrated supernova analysis framework to prepare an analysis pipeline for treating galactic supernovae observations in the near future. This framework deals with the core-collapse, bounce, and proto-neutron star cooling processes, as well as with neutrino detection on Earth in a consistent manner. We have developed a new long-time supernova simulation in one dimension that explodes successfully and computes the neutrino emission for up to 20 seconds. Using this model we estimate the resulting neutrino signal at the Super-Kamiokande detector to be about 1800 events for an explosion at 10 kpc, and we discuss the implications of this. We compare this result with the SN 1987A observation to test its reliability.