A. Colaiuda, K. D. Kokkotas
We study coupled axial and polar axisymmetric oscillations of a neutron star
endowed with a strong magnetic field, having both poloidal and toroidal
components. The toroidal component of the magnetic field is driving the
coupling between the polar and axial oscillations. The star is composed of a
fluid core as well as a solid crust. Using a two dimensional general
relativistic simulation and a magnetic field B = 10^16 G, we study the change
in the polar and axial spectrum caused by the coupling. We find that the axial
spectrum suffers a dramatic change in its nature, losing its continuum
character. In fact, we find that only the 'edges' of the continua survive,
generating a discrete spectrum. As a consequence the crustal frequencies, that
in our previous simulation could be absorbed by the continua, if they were
embedded inside it, are now long living oscillations. They may lose their
energy only in the very special case that they are in resonance with the
'edges' of the continua.
View original:
http://arxiv.org/abs/1112.3561
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