1111.0514 (Anna L. Watts)
Anna L. Watts
The most strongly magnetized neutron stars, the magnetars, have spectacular
outbursts of gamma-ray flares powered by decay of the magnetic field. The
rapidly changing field is strong enough that it should be able to stress and
rupture the star's crust, with potentially interesting seismic consequences.
This was confirmed in dramatic fashion a few years ago with the discovery of
long-lived seismic vibrations excited by rare giant flares. The starquakes
associated with the giant flares are, it seems, so catastrophic that they leave
the whole star ringing. These discoveries have opened up the possibility of
using asteroseismology to study the extreme conditions of the neutron star
interior - the dense matter equation of state in crust and core, and the core
magnetic field. This chapter reviews the main observational properties of the
oscillations seen in the giant flares, and the state of the art in terms of
theoretical models of global seismic vibrations in magnetars. I discuss efforts
to extend oscillation searches to smaller magnetar bursts (which are more
frequent but less energetic), and the role that crust rupturing might play in
triggering magnetar flares and exciting global seismic oscillations.
View original:
http://arxiv.org/abs/1111.0514
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