Pulsar acceleration by asymmetric emission of sterile neutrinos

A convincing explanation for the observed pulsar large peculiar velocities is still missing. We argue that any viable particle physics solution would most likely involve the resonant production of a non-interacting neutrino ${\nu }_s$ of mass $m_{{\nu }_s}\sim 20$–50 keV. We propose a model where anisotropic magnetic field configurations strongly bias the resonant spin flavour precession of tau antineutrinos into ${\nu }_s$. For internal magnetic fields $B_{int} \gsim 10^{15}$Ga$\bar\nu_\tau$-$\nu_s$transitionmagneticmomentoftheorderof$10^{-12}$Bohrmagnetonsisrequired\mathrm{.}Theasymmetricemissionof$\nu_s$ from the core can produce sizeable natal kicks and account for recoil velocities of several hundred kilometers per second.