Evolutionary tracks of massive stars with different rotation and metallicity in neutrino H-R diagram

TL;DR

This study explores how rotation and metallicity influence neutrino luminosity throughout the evolution of massive stars, revealing effects on core processes and the impact of neutrino magnetic moments.

Contribution

It provides new insights into the effects of rotation, metallicity, and neutrino magnetic moments on the neutrino luminosity and evolution of massive stars in a neutrino Hertzsprung-Russell diagram.

Findings

Neutrino luminosity increases with stellar mass and decreases with metallicity during hydrogen burning.

Rapid rotation enhances neutrino luminosity during main sequence and core burning phases.

Neutrino magnetic moments do not significantly affect stellar evolution or core collapse outcomes.

Abstract

Neutrino losses play a crucial role in the evolution of massive stars. We study the neutrino luminosity of stars ranging from 20 to 90 M_{\odot} from Zero Age Main Sequence (ZAMS) to Fe Core Collapse (FeCC) with different rotation and metallicity in a neutrino Hertzsprung-Russell diagram. In our simulations, we consider {\omega}/{\omega}crit = 0 and 0.7 to represent non-rotation and high rotation, respectively, and set the metallicities to 0.014, 0.001, and 0.0001. During hydrogen burning stages, neutrino luminosity primarily originates from CNO cycle, and increases with higher stellar mass while decreasing with increasing metallicity. For the high metallicity models (Z = 0.014) during the helium burning stage, the reduction of the hydrogen envelope caused by a larger mass loss rate leads to a gradual decrease in neutrino luminosity. The rapid rotation results in extra mixing inside massive stars, which increases the neutrino luminosity during main sequence (MS), while decreases the neutrino luminosity during helium burning phase. Simultaneously, the rapid rotation also increases CO core mass, which enhances the neutrino luminosity during C and O burning phase. We also investigate the effect of neutrino magnetic moment (NMM) on the massive stars. We find that the energy loss caused by the NMM does not have effects on the evolutionary destiny of massive stars, and it does not significant change the compactness at the time of Fe core collapse.