Electromagnetic damping of neutron star oscillations

Journal Article · Fri Jun 15 04:00:00 EDT 1984 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/162152· OSTI ID:6468869

McDermott, P N; Savedoff, M P; Van Horn, H M; Zweibel, E G; Hansen, C J

Nonradial pulsations of a neutron star with a strong dipole magnetic field cause emission of electromagnetic radiation. Here we compute the power radiated to vacuum by neutron star g-mode pulsations and by torsional oscillations of the neutron star crust. For the low-order quadrupole fluid g-modes we have considered, we find electromagnetic damping to be considerably more effective than gravitational radiation. For example, a 0.5 M/sub sun/ neutron star with a core temperature approx.10/sup 7/ K has a g/sub 1/-mode period of 371 ms; for this mode were find the electromagnetic damping time to be tau/sub FM/approx.0.3 s, assuming the surface magnetic field strength of the neutron star to be B/sub 0/approx.10/sup 12/ gauss. This is considerably less than the corresponding gravitational radiation time tau/sub GR/approx.3 x 10/sup 17/ yr. For dipole g-mode oscillations, there is no gravitational radiation, but electromagnetic damping and ohmic dissipation are efficient damping mechanisms. For dipole torsional oscillations, we find that electromagnetic damping again dominates, with tau/sub EM/approx.5 yr. Among the cases we have studied, quadrupole torsional oscillations appear to be dominated by gravitational radiation damping, with tau/sub GR/approx.10/sup 4/ yr, as compared with tau/sub EM/approx.2 x 10/sup 7/ yr.

• Research Organization: Department of Physics and Astronomy and C. E. Kenneth Mees Observatory, University of Rochester
• OSTI ID: 6468869
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 281:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COSMIC RADIO SOURCES
DAMPING
ELECTRIC HEATING
ELECTROMAGNETIC RADIATION
ENERGY LOSSES
GRAVITATIONAL RADIATION
HEATING
JOULE HEATING
LOSSES
MAGNETIC FIELDS
MAGNETIC STARS
NEUTRON STARS
OSCILLATION MODES
OSCILLATIONS
PLASMA HEATING
PULSARS
RADIATIONS
RESISTANCE HEATING
STARS
STELLAR RADIATION