Pre-supernova neutrino emissions from ONe cores in the progenitors of core-collapse supernovae: are they distinguishable from those of Fe cores?

Understand

Aiming to distinguish two types of progenitors of core collapse supernovae, i.e., one with a core composed mainly of oxygen and neon (abbreviated as ONe core) and the other with an iron core (or Fe core), we calculated the luminosities and spectra of neutrinos emitted from these cores prior to gravitational collapse, taking neutrino oscillation into account.

• We found that the total energies emitted as $\bar{\nu}_e$ from the ONe core are $\lesssim 10^{46}\ {\rm erg}$, which is much smaller than $\sim 10^{47}\ {\rm erg}$ for Fe cores.
• The average energy, on the other hand, is twice as large for the ONe core as those for the Fe cores.
• The neutrinos produced by the plasmon decays in the ONe core are more numerous than those from the electron-positron annihilation in both cores but they have much lower average energies $\lesssim 1\ {\rm MeV}$.