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Effect of interstellar density fluctuations on signal dispersion measure

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Abstract

The effect of electron number density fluctuations in the interstellar medium on signals from pulsars is studied in terms of the frequency dependent signal dispersion. It is shown that if the density fluctuations are representative of long wavelength (1∼100 pc) [or large scale length (1∼100 pc)] disturbances in the interstellar gas, then the observed signal dispersion is not a measure of the integral of the electron number density in the line of sight. Evidence has been presented elsewhere for believing that such long wavelength disturbances should exist in the interstellar gas, so this result indicated that some care must be exercised in the interpretation of signal dispersion measurements from pulsars.

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Authors and Affiliations

  1. Enrico Fermi Institute and Dept of Physics, University of Chicago, Chicago, Ill., USA

    I. Lerche (Alfred P. Sloan Foundation Fellow)

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  1. I. Lerche
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Lerche, I. Effect of interstellar density fluctuations on signal dispersion measure. Astrophys Space Sci 6, 287–292 (1970). https://doi.org/10.1007/BF00651229

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