Analytic solutions for neutrino-light curves of core-collapse supernovae

TL;DR

This paper derives analytic solutions for neutrino light curves from core-collapse supernovae, enabling estimation of physical properties like PNS mass and radius from observational data.

Contribution

It introduces explicit analytic formulas connecting neutrino observables with physical parameters of protoneutron stars, based on the diffusion approximation.

Findings

Analytic solutions match numerical models after a few seconds post-explosion.

Formulas relate neutrino luminosity and energy to PNS mass, radius, and other parameters.

Provides a method for rough estimation of supernova core properties from neutrino data.

Abstract

Neutrinos are a guaranteed signal from supernova explosions in the Milky Way, and a most valuable messenger that can provide us with information about the deepest parts of supernovae. In particular, neutrinos will provide us with physical quantities, such as the radius and mass of protoneutron stars (PNS), which are the central engine of supernovae. This requires a theoretical model that connects observables such as neutrino luminosity and average energy with physical quantities. Here, we show analytic solutions for the neutrino-light curve derived from the neutrino radiation transport equation by employing the diffusion approximation and the analytic density solution of the hydrostatic equation for a PNS. The neutrino luminosity and the average energy as functions of time are explicitly presented, with dependence on PNS mass, radius, the total energy of neutrinos, surface density, and opacity. The analytic solutions provide good representations of the numerical models from a few seconds after the explosion and allow a rough estimate of these physical quantities to be made from observational data.