The Kelvin-Helmholtz cooling epoch , lasting tens of seconds after the birth of a neutron star in a successful core-collapse supernova , is accompanied by a neutrino-driven wind .
For magnetar-strength ( \sim 10 ^ { 15 } G ) large scale surface magnetic fields , this outflow is magnetically-dominated during the entire cooling epoch .
Because the strong magnetic field forces the wind to co-rotate with the protoneutron star , this outflow can significantly effect the neutron star ’ s early angular momentum evolution , as in analogous models of stellar winds ( e.g .
Weber & Davis 1967 ) .
If the rotational energy is large in comparison with the supernova energy and the spindown timescale is short with respect to the time required for the supernova shockwave to traverse the stellar progenitor , the energy extracted may modify the supernova shock dynamics significantly .
This effect is capable of producing hyper-energetic supernovae and , in some cases , provides conditions favorable for gamma ray bursts .
We estimate spindown timescales for magnetized , rotating protoneutron stars and construct steady-state models of neutrino-magnetocentrifugally driven winds .
We find that if magnetars are born rapidly rotating , with initial spin periods ( P ) of \sim 1 millisecond , that of order 10 ^ { 51 } -10 ^ { 52 } erg of rotational energy can be extracted in \sim 10 seconds .
If magnetars are born slowly rotating ( P \gtrsim 10 ms ) they can spin down to periods of \sim 1 second on the Kelvin-Helmholtz timescale .