Distinguish between spiral and elliptical galaxies in terms of the presence or absence of a disk component and halo component. How does this difference explain the lack of hot, young stars in elliptical galaxies?

lack a significant disk component, although both types have the halo component.

Explanation:

The absence of the disk components in the elliptical galaxies is a major difference that occurs in the spiral and the elliptical as the elliptical galaxies lacks disk components they would not have an active star formation taking place. As the halo does not have that star formation properties and are small in nature and thus have much older stars than in spiral galaxies.