galaxy puzzle

3. the observation in physical cosmology that galaxies are moving away from Earth at speeds proportional to their distance.
4. a tightly packed group of stars within a larger star formation
7. star having a regular cycle of brightness with a frequency related to its luminosity
10. he ratio of the speed of recession of a galaxy (due to the expansion of the universe) to its distance from the observer.
12. a galaxy that emits up to thousands of times more energy than a normal galaxy.
15. a huge collection of gas, dust, and billions of stars and their solar systems, held together by gravity.

1. a galaxy that does not have a distinct regular shape, unlike a spiral or an elliptical galaxy
2. structure that consists of anywhere from hundreds to thousands of galaxies that are bound together by gravity
5. a nearly spherical volume of thinly scattered stars, globular clusters of stars, and tenuous gas observed surrounding spiral galaxies
6. are twisted collections of stars and gas that often have beautiful shapes.
8. a smooth ellipsoidal or spherical appearance, and they have far less structure than spiral galaxies do
9. a phenomenon where the wavelength of light is lengthened as it travels through expanding space.
11. galaxy with a black whole in the center
13. a disk component of the Milky Way that contains stars, gas, and dust in circular coplanar motion around the galactic center.
14. a galaxy group that includes the Milky Way.