17-4 Ring and Elliptical Galaxies

What is a galaxy?

• A small collection of stars and dust

• A large but isolated collection of stars, interstellar gas and dust, star clusters, and nebulae

• A single star with planets

• A cluster of planets

Why are galaxies more likely to collide than stars within a galaxy?

• Galaxies are smaller than stars

• Stars move faster than galaxies

• The distances between galaxies are smaller than the distances between stars within a galaxy

• Galaxies are attracted to stars

What happens when one galaxy strikes another near its center?

• The target galaxy's matter moves inwards

• The target galaxy's matter moves outwards in the shape of a ring

• The target galaxy disappears

• The target galaxy becomes a black hole

What is the result of the expanding shock wave in a ring galaxy?

• A decrease in star formation

• A big burst of star formation centered on the nucleus of the target galaxy

• The destruction of the galaxy

• The creation of a black hole

What is the nearest galaxy to the Milky Way?

• Within a diameter of our own galaxy

• 10 times the diameter of our own galaxy

• 100 times the diameter of our own galaxy

• 1000 times the diameter of our own galaxy

What is the main reason stars within a galaxy do not collide during a galaxy collision?

• Stars are too small

• Stars move too fast

• The distances between stars are vast

• Stars repel each other

What is the shape of the matter movement in a ring galaxy after a collision?

• Spiral

• Linear

• Ring

• Square

What is the analogy used to describe the expanding shock wave in a ring galaxy?

• A drop of milk splashing in a glass

• A stone thrown in a pond

• A car moving on a road

• A bird flying in the sky

What is the main topic of the document?

• The life cycle of stars

• The formation of black holes

• Galaxy collisions: Ring & Elliptical Galaxies

• The structure of the Milky Way

What happens when two galaxies orbit and collide repeatedly?

• They form a spiral galaxy

• They form a ring galaxy

• They merge into an elliptical galaxy

• They remain separate