Probing protoneutron star density profile from neutrino signals

TL;DR

This paper investigates how neutrino signals from supernovae can reveal the density profile of protoneutron stars by simulating flavor conversion and analyzing model sensitivities.

Contribution

It introduces a numerical simulation method for neutrino flavor conversion in protoneutron stars and assesses how neutrino signals can validate star structure models.

Findings

Neutrino survival probabilities depend on the star's density profile.

The simulation algorithm accurately conserves unitarity.

Neutrino signals can test protoneutron star models.

Abstract

Supernovae of Type II is a phenomenon that occurs at the end of evolution of massive stars when the iron core of the star exceeds a mass limit. After collapse of the core under gravity the shock wave alone does not succeed in expelling the mass of the star and in this sense the role of neutrinos is the most important mechanism to do so. During the emission of neutrinos flavor conversion is possible, related the phenomenon of oscillations, which however depends directly on the particular density profile of the medium. In this paper we present results of numerical simulations of neutrino flavor conversion in protoneutron stars and after collapse. The probabilities of survival for a given flavor in a complete three-flavors framework is estimated through an algorithm which conserves unitarity to a high degree of accuracy. The sensitivity of the results to the different adopted models for the protoneutron star structure is examined in detail demonstrating how the neutrino signal could be used to check the validity of models.