Velocities of pulsars and neutrino oscillations

Abstract

Neutrino oscillations, biased by the magnetic field, alter the shape of the neutrinosphere in a cooling protoneutron star emerging from the supernova collapse. The resulting anisotropy in the momentum of outgoing neutrinos can be the origin of the observed proper motions of pulsars. The connection between the pulsars velocities and neutrino oscillations results in a prediction for the tau neutrino mass of order 100 eV.

Figures (1)

• Figure 1: If the resonant oscillation $\nu_\tau \rightarrow \nu_e$ takes place between the electron neutrinosphere, $S_e$, and that of $\nu_\mu, \nu_{\tau}, \bar{\nu}_\mu, \bar{\nu}_{\tau}$ and $\bar{\nu}_e$, $S_\mu$, then the effective$\tau$-neutrinosphere coincides with the surface of resonance, $S^{({\rm eff})}_\tau$. The latter is affected by the magnetic field. Therefore, the $\tau$-neutrinos emitted in different directions come from the regions of different temperatures. The resulting anisotropy in the momentum of the outgoing neutrinos can be the origin of the pulsar "kick" velocity, whose magnitude depends on the magnetic field.