ASTRO In the literature: partially resolved

Origin of neutron star birth kicks and spins

In plain words

Neutron stars are born moving hundreds of times faster than a rifle bullet and spinning, possibly because the explosion is lopsided.

Precise statement

Determine whether asymmetric mass ejection (gravitational tug of slow ejecta) and anisotropic neutrino emission in 3D explosions reproduce the pulsar velocity distribution (mean $\sim 4e7\ \mathrm{cm/s}$, tail above 1e8 cm/s), birth spin periods (tens to hundreds of ms) and any spin-kick alignment. Answer: predicted distributions from simulation suites compared with pulsar proper motions.

What would settle it

Simulated kick and spin distributions statistically matching pulsar data, and remnant ejecta asymmetries (for example Ti-44 maps) correlated with kick direction.