| definition |
A rotating neutron star that emits a radio beam that is centered on the magnetic axis
of the neutron star. As the magnetic axis and hence the beam are inclined to the rotation
axis, a pulse is seen every time the rotation brings the magnetic pole region of the
neutron star into view. In this way the pulsar acts much as a light house does, sweeping
a beam of radiation through space. The pulse or spin periods range from 1.4 milliseconds
to 8.5 seconds. As neutron stars concentrate an average of 1.4 solar masses on a diameter
of only 20 km, pulsars are exceedingly dense and compact, representing the densest
matter in the observable Universe. The pulsar radiation, chiefly emitted in radio
frequencies (0.1-1 GHz), is highly polarized. The exact mechanism by which a pulsar
radiates is still a matter of vigorous investigation. Simply put, an enormous electric
field is induced by the rotation of a magnetized neutron star. The force of this field
exceeds gravity by ten to twelve orders of magnitudes. Charged particles are whereby
pulled out from the stellar surface resulting in a dense, magnetized plasma that surrounds
the pulsar (magnetosphere). The charged particles flow out of the magnetic polar caps
of the neutron star, following the open magnetic field lines. The acceleration of
the charged particles along the curved magnetic field lines will cause them to radiate.
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