SF1-2 - (SF1) Strong (EM) Field Physics and Astrophysics - (SF2) Ground experiments and astrophysical observations in Strong Field Physics |
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Speaker |
Ahmedov, Bobomurat |
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Coauthors |
Morozova, Viktoriya; Zanotti, Olindo |
| Talk Title |
General Relativistic Plasma Magnetospheres Of Slowly Rotating And Oscillating Magnetized Neutron Stars |
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Abstract |
The magnetosphere of a slowly rotating magnetized neutron star subject to toroidal oscillations in the relativistic regime is studied. Under the assumption of a zero inclination angle between the magnetic moment and the angular momentum of the star, we analyse the Goldreich-Julian charge density and derive a second-order di erential equation for the electrostatic potential. The analytical solution of this equation in the polar cap region of the magnetosphere shows the modification induced by stellar toroidal oscillations on the accelerating electric field and on the charge density. We also find that, after decomposing the oscillation velocity in terms of spherical harmonics, the first few modes with m = 0, 1 are responsible for energy losses that are almost linearly dependent on the amplitude of the oscillation and that, for the mode (l,m) = (2, 1), can be a factor about 8 larger than the rotational energy losses, even for a velocity oscillation amplitude at the star surface small. The results obtained clarify the extent to which stellar oscillations are reected in the time variation of the physical properties at the surface of the rotating neutron star, mainly by showing the existence of a relation between spindown and the oscillation amplitude. Finally, we propose a qualitative model for the explanation of the phenomenology of intermittent pulsars. The idea is that stellar oscillations, periodically excited by star glitches, can create relativistic winds of charged particles because of the additional electric field. When the stellar oscillations damp, the pulsar shifts below the death line in the P-B diagram, thus entering the OFF invisible state of intermittent pulsars. |
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