Issue |
A&A
Volume 395, Number 1, November III 2002
|
|
---|---|---|
Page(s) | 201 - 208 | |
Section | Interstellar and circumstellar matter | |
DOI | https://doi.org/10.1051/0004-6361:20021270 | |
Published online | 29 October 2002 |
Nonradial oscillations of neutron stars with a solid crust
Analysis in the relativistic Cowling approximation
1
Centro Multidisciplinar de Astrofísica – CENTRA, Departamento de Física, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal e-mail: yoshida@fisica.ist.utl.pt; yoshida@astr.tohoku.ac.jp
2
Astronomical Institute, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan e-mail: lee@astr.tohoku.ac.jp
Corresponding author: S. Yoshida, yoshida@astr.tohoku.ac.jp
Received:
25
June
2002
Accepted:
30
August
2002
Nonradial oscillations of relativistic neutron stars with a solid
crust are computed in the relativistic Cowling approximation, in
which all metric perturbations are ignored. For the modal analysis,
we employ three-component relativistic neutron star models with a
solid crust, a fluid core, and a fluid ocean. As a measure for the
relativistic effects on the oscillation modes, we calculate the
relative frequency difference defined as
, where
and
are, respectively, the relativistic and
the Newtonian oscillation frequencies. The relative difference
takes various values for different oscillation
modes of the neutron star model, and the value of
for a given mode depends on the physical properties of the models.
We find that
is less than ~0.1 for most of
the oscillation modes we calculate, although there are a few exceptions
such as the fundamental (nodeless) toroidal torsional modes in the crust,
the surface gravity modes confined in the surface ocean, and the core
gravity modes trapped in the fluid core. We also find that the modal
properties, represented by the eigenfunctions, are not strongly affected
by introducing general relativity. It is however shown that the mode
characters of the two interfacial modes, associated with the core/crust
and crust/ocean interfaces, have been interchanged between the two
through an avoided crossing when we move from Newtonian dynamics to
general relativistic dynamics.
Key words: relativity / stars: neutron / stars: oscillations
© ESO, 2002
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.