Kyle Parfrey, Andrei M. Beloborodov, Lam Hui
We present the first simulations of evolving, strongly twisted magnetospheres
of magnetars. Slow shearing of the magnetar crust is seen to lead to a series
of magnetospheric expansion and reconnection events, corresponding to X-ray
flares and bursts. The simulations include rotation of the neutron star and the
magnetic wind through the light cylinder. We study how the increasing twist
affects the spindown rate of the star, finding that a dramatic increase in
spindown occurs. Particularly spectacular are explosive events caused by sudden
opening of large amounts of overtwisted magnetic flux, which may be associated
with the observed giant flares. These events are accompanied by a short period
of ultra-strong spindown, resulting in an abrupt increase in spin period, such
as was observed in the giant flare of SGR 1900+14.
View original:
http://arxiv.org/abs/1201.3635
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