Program
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Signatures of neutron star oscillations in post-glitch emission of radiopulsars
Andrey Timokhin
Sternberg Astronomical Institute
Abstract:
Experimental determination of neutron stars eigenmodes parameters
would provide important information about internal structure of the
neutron stars. Isolated NSs should be more suitable for such studies,
because their power spectra are not contaminated by numerous
instabilities in accreted material. The vast majority of known
isolated NSs are radiopulsars, in ~ 50 of them glitches are
observed. Glitches can excite neutron star oscillations, because they
are connected with transfer of rotation energy from one stellar
component (core) to another (crust). The main attention in this work
is drawn to distortion of pulsar magnetosphere by neutron star
oscillations. Pulsar "standard model" of rotating magnetized
conducting sphere surrounded by plasma is generalized in its essential
parts for the case of oscillating star. Goldreich-Julian charge
density, electromagnetic energy losses, as well as polar cap scenario
of particle accelerations, are considered. The changes in the
Goldreich-Julian charge density due to star pulsations for oscillation
modes with high harmonic numbers (l,m) are essential, and will lead to
substantially distortion of accelerating electric field in pulsar
polar cap. This can result in remarkable changes of individual pulse
profiles of radiopulsars. It is shown, that for moderately optimistic
scenario of NS's oscillations excitation by the glitch, such changes
in pulsar radiation could be detected by contemporary radiotelescopes.
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