How does galaxy composition typically relate to the age of the stars in the galaxy?(1 point)

Question

Responses

Star aging emits gas and dust, so galaxies with the youngest stars typically have the lowest proportions of dust and gas.
Star aging emits gas and dust, so galaxies with the youngest stars typically have the lowest proportions of dust and gas.

Stars form from dust and gas, so galaxies with younger stars typically consist of higher proportions of dust and gas than other galaxies.
Stars form from dust and gas, so galaxies with younger stars typically consist of higher proportions of dust and gas than other galaxies.

Star formation consumes dust and gas, so galaxies where stars are oldest typically consist of higher proportions of dust and gas than other galaxies.
Star formation consumes dust and gas, so galaxies where stars are oldest typically consist of higher proportions of dust and gas than other galaxies.

Star formation and the presence of young stars is common across galaxies, regardless of the proportions of dust and gas present.

Answer 1

The correct response is:

"Stars form from dust and gas, so galaxies with younger stars typically consist of higher proportions of dust and gas than other galaxies."

This is because younger stars are often formed in regions with abundant dust and gas, indicating active star formation, while older stars tend to have formed earlier when these materials were more prevalent. As stars age and go through their life cycles, they can contribute to the reduction of available gas and dust through processes like supernovae, which disperse materials into the interstellar medium. Hence, galaxies with a high proportion of young stars usually have more gas and dust available for star formation.