r-modes of neutron stars with a solid crust

Shijun Yoshida, Umin Lee

Research output: Contribution to journalArticlepeer-review

29 Citations (Scopus)


We investigate the properties of r-mode oscillations of a slowly rotating neutron star with a solid crust by taking account of the effects of the Coriolis force. For the modal analysis we employ three-component neutron star models that are composed of a fluid core, a solid crust, and a surface fluid ocean. For the three-component models, we find that there exist two kinds of r-modes, that is, those confined in the surface fluid ocean and those confined in the fluid core, which are most important for the r-mode instability. The r-modes do not have any appreciable amplitudes in the solid crust if rotation rate of the star is sufficiently small. We find that the core r-modes are strongly affected by mode coupling with the crustal torsional (toroidal) modes and lose their simple properties of the eigenfunction and eigenfrequency as functions of the angular rotation velocity Ω. This indicates that the extrapolation formula, which is obtained in the limit of Ω → 0, cannot be used to examine the r-mode instability of rapidly rotating neutron stars with a solid crust unless the effects of mode coupling with the crustal torsional modes are correctly taken into account.

Original languageEnglish
Pages (from-to)1121-1125
Number of pages5
JournalAstrophysical Journal
Issue number2 PART 1
Publication statusPublished - 2001 Jan 10


  • Dense matter
  • Instabilities
  • Stars: neutron
  • Stars: oscillations
  • Stars: rotation

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'r-modes of neutron stars with a solid crust'. Together they form a unique fingerprint.

Cite this