What does a huge redshift in a quasar's spectrum indicate?

A huge redshift in a quasar's spectrum primarily indicates the quasar is moving away from us at a significant speed, which is a result of the expansion of the universe. This redshift is quantified as the change in the wavelength of light emitted by the quasar; longer wavelengths indicate that the quasar is receding.

In cosmology, the redshift (often represented by 'z') is directly related to the distance of the object from the observer. The greater the redshift, the faster the object is receding, and this is linked to how far away it is. This relationship is rooted in Hubble's Law, which states that galaxies (and quasars) that are farther away are receding from us faster due to the expansion of space.

While the redshift does indicate the speed of the quasar, it is the measurement of the redshift itself that provides critical information about the quasar's distance from us. Therefore, a huge redshift is an essential clue in determining how far away the quasar is located in the universe, making the distance to the quasar the correct interpretation of a significant redshift.

Understanding redshift is fundamental in astronomy, as it links to various aspects of cosmology and the structure