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Non-cosmological redshifts of spectral lines


We showed in a recent report1 (see also refs 2–4) that the normalized spectrum of light will, in general, change on propagation in free space. We also showed that the normalized spectrum of light emitted by a source of a well-defined class will, however, be the same throughout the far zone if the degree of spectral coherence of the source satisfies a certain scaling law. The usual thermal sources appear to be of this kind. These theoretical predictions were subsequently verified by experiments5. Here, we demonstrate that under certain circumstances the modification of the normalized spectrum of the emitted light caused by the correlations between the source fluctuations within the source region can produce redshifts of spectral lines in the emitted light. Our results suggest a possible explanation of various puzzling features of the spectra of some stellar objects, particularly quasars.

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Wolf, E. Non-cosmological redshifts of spectral lines. Nature 326, 363–365 (1987).

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