If the redshift is an accurate indication of the distance to that galaxy, then this is considered acosmological redshift.

Question

Quizplus · Accepted Answer

Cosmological redshift is caused by the expansion of the universe and is proportional to the distance between the observer and the galaxy. Therefore, if the redshift is an accurate indication of the distance to the galaxy, it is considered a cosmological redshift. A cosmological redshift occurs when the wavelength of light from a distant galaxy is stretched due to the expansion of the universe, causing the galaxy to appear further away than it actually is. This is a reliable way to determine the distance to a galaxy and is considered a cosmological redshift as opposed to other sources of redshift such as Doppler shifts caused by the motion of stars within the galaxy.

If the Redshift Is an Accurate Indication of the Distance