enter image description here Pulsars emit one pulse that arrives at later times at lower frequencies. The reason I have read is:

Since radio waves are a very low frequency form of light/electromagnetic radiation (ie photons), they are nothing more than an oscillating electric and magnetic field. In the presence of charged particles such as protons and electrons, the electrostatic interaction between the light and the charged particles causes a delay in the propagation of the light, with the delay being a function of radio frequency and the masses of the charged particles.

This doesn't explain how the em wave is "dispersed" or slowed down. if it was truly slowed down, the period of the lower frequencies would also be higher...

From my understanding from the information presented by Felix Lockman the period is a combination of its rest period caused by the spinning neutron star and any doppler shift. The doppler shift of the ~1 second pulses of the spinning star with a magentic beam sweeping past our view and the doppler shift of the frequency of the em wave radiation is the same thing. These occur at the same intervals for all frequencies.

  • 1
    $\begingroup$ Have you considered that all EMR passing through matter has a propagation speed less than c? We summarize that in an index of refraction. The index of refraction is wavelength dependent and that effect is called dispersion. $\endgroup$
    – Bill N
    Commented May 9, 2018 at 12:57
  • $\begingroup$ @BillN I have a second question then. Why are the pulses at lower frequencies not more spread out? $\endgroup$ Commented May 9, 2018 at 19:25


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.