A distant quasar shows a large redshift -- one so large, in fact, that the features we now see in the visible-light region of the spectrum would be invisible to us, were it not for the redshift. What band of the electro-magnetic spectrum were these features most likely in, before the spectrum was redshifted?

Question

Quizplus · Accepted Answer

The large redshift of a quasar indicates that the electromagnetic radiation it emitted has been stretched to longer wavelengths as the universe expanded. Features originally in the ultraviolet (UV) part of the spectrum would be shifted into the visible range, making them observable to us despite the vast distance.

A Distant Quasar Shows a Large Redshift -- One So