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A toy model for global magnetar oscillation

  • Kostas GlampedakisEmail author
  • Lars Samuelsson
  • Nils Andersson
Conference paper

Abstract

The presence of a magnetic field in a neutron star interior results in a dynamical coupling between the fluid core and the elastic crust. We consider a simple toy-model where this coupling is taken into account and compute the system’s mode oscillations. Our results suggest that the notion of pure torsional crust modes is not useful for the coupled system, instead all modes excite Alfvén waves in the core. However, we also show that among a rich spectrum of global MHD modes the ones most likely to be excited by a fractured crust are those for which the crust and the core oscillate in concert. For our simple model, the frequencies of these modes are similar to the “pure crustal” frequencies. We advocate the significant implications of these results for the attempted theoretical interpretation of QPOs during magnetar flares in terms of neutron star oscillations.

Keywords

Neutron stars Oscillations Magnetars 

PACS

04.40.Dg 97.60.Jd 

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Copyright information

© Springer 2007

Authors and Affiliations

  • Kostas Glampedakis
    • 1
    Email author
  • Lars Samuelsson
    • 1
  • Nils Andersson
    • 1
  1. 1.School of MathematicsUniversity of SouthamptonSouthamptonUK

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