Date of Award
Doctor of Philosophy (PhD)
Garry E. Copeland
Charles I. Sukenik
This dissertation investigates the neutron star magnetic field from generation to radiation production. We have investigated the spontaneous magnetization process to explain the magnetic field generation. This magnetization is then applied to determine the electromagnetic field structure of the neutron star. As an application of these two calculations, we briefly investigate several radiation mechanisms that are closely related to stellar magnetic fields.
Neutron star magnetic field generation is studied through the spontaneous magnetization process. This process was studied in the non-relativistic, ultra-relativistic, and rigorous relativistic dispersion regimes for the neutrons. Both analytical and numerical approaches show that a phase transition is present for a density near 1038cm−3 and a temperature near 109K. This density is consistent with most neutron star models.
Using the magnetized interior, the neutron star electromagnetic field is derived from the vector potential. The derived magnetic field is more complicated than just a magnetic dipole which is the most common approximation to the magnetic field. The electromagnetic field structure is derived under the Goldreich-Julian approach.
Finally this electromagnetic field is applied to three radiation mechanisms in attempt to understand the high-frequency radiation observed from neutron stars. The processes studied are curvature radiation, pair production, and synchrotron radiation. The curvature radiation is most greatly affected by the electromagnetic field because the radius of curvature is reduced by a factor 10 when just the quadrapole term is included. This directly affects the number of photons energetic enough to undergo pair production. These electron-positron pairs are also more energetic and the synchrotron radiation spectrum is affected by not only the injection angle but the magnetic field curvature as well.
Thurman, Hugh O..
"Neutron Star Electromagnetic Field Structure"
(2004). Doctor of Philosophy (PhD), Thesis, Physics, Old Dominion University, DOI: 10.25777/m1nr-v189