An astronomer discovers an extremely luminous galaxy with broad emission lines that have very large redshifts.This is most likely a:
A) Seyfert galaxy.
B) barred spiral galaxy.
C) spiral galaxy.
D) quasar.

Question

Quizplus · Accepted Answer

The presence of broad emission lines with very large redshifts indicates that the galaxy is very distant and that the emitted light has been shifted to longer (redder) wavelengths due to the expansion of the universe. Such highly redshifted emission lines are commonly observed in quasars, which are extremely luminous galaxies powered by accretion onto supermassive black holes in their centers. Seyfert galaxies, barred spiral galaxies, and spiral galaxies can also show emission lines, but these would not typically have very large redshifts.

An Astronomer Discovers an Extremely Luminous Galaxy with Broad Emission