For very distant galaxies, what is identified as the primary driver causing the observed redshift?

Answer

The expansion of space itself.

While motion through space causes a Doppler shift for nearby objects, the predominant cause of redshift for very distant galaxies is the metric expansion of the space fabric through which the photons travel.

For very distant galaxies, what is identified as the primary driver causing the observed redshift?

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Why Is The Universe Expanding? Red-Shift & Doppler Effect ...

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