APT3 - Extreme Properties of Neutron Stars: Observations and Theory |
Speaker_ |
Glampedakis, Kostas |
Co-autors |
N. Andersson and L. Samuelsson |
Talk _ |
Elastic or magnetic? A toy-model of global magnetar oscillations and implications for QPOs during flares. |
Abstract _ |
By means of a simple toy-model we estimate global MHD modes of a neutron star, taking into account the magnetic coupling between the elastic crust and the fluid core. Our results suggest that the modes most likely to be excited by a fractured crust, during a magnetar flare, are the ones that establish a resonance between the oscillating crust and core. The predicted frequencies are similar to the known crustal mode frequencies. Furthermore, our model offers a plausible explanation for the origin of the lower frequency ( < 30 Hz ) QPOs detected in the Dec2004 giant flare of SGR 1806-20. |