2 reasons y elliptical galaxies are considered to be older & more evolved than spiral galaxies.

Are they considered to be older because they have little instellar matter and because they rarely form new stars like the other galaxies do. They seem to be more evolved than the spiral galaxies because?

A little help on this would be appreicated, thanks

Yes, elliptical galaxies are generally considered to be older and more evolved than spiral galaxies. Here are two reasons that support this viewpoint:

1. Interstellar matter: Elliptical galaxies have relatively low amounts of interstellar matter, such as gas and dust, compared to spiral galaxies. Interstellar matter is crucial in the formation of new stars and is typically more abundant in spiral galaxies. The scarcity of interstellar matter in elliptical galaxies suggests that star formation activity has already taken place and is now in decline. This indicates that most of the stellar evolution has already occurred in elliptical galaxies.

2. Star formation: Elliptical galaxies are known for having little to no ongoing star formation. While spiral galaxies continuously form new stars in their spiral arms, elliptical galaxies lack prominent spiral structures and have low levels of star formation. The absence of significant ongoing star formation implies that elliptical galaxies have exhausted or used up most of their available gas reservoirs, which were likely consumed during earlier stages of star formation. Therefore, the reduced star formation activity in elliptical galaxies suggests that they have evolved past the peak of their star-forming phase.

You are partially correct! Elliptical galaxies are indeed considered to be older and more evolved than spiral galaxies. Here are two reasons for that:

1. Lack of Interstellar Matter: Elliptical galaxies have very little interstellar matter compared to spiral galaxies. Interstellar matter includes gas and dust clouds from which new stars can form. The low amounts of interstellar matter in elliptical galaxies indicate that they have gone through significant periods of star formation in the past and have since used up or expelled most of their interstellar material.

To support this reason, you can look for observations or research papers that compare the amounts of interstellar matter between elliptical and spiral galaxies. These studies may utilize various techniques such as analyzing the spectroscopic signatures of the galaxies or examining their dust content.

2. Limited Star Formation: Elliptical galaxies also typically have a lower rate of ongoing star formation compared to spiral galaxies. While spiral galaxies continuously form new stars in their rotating arms, elliptical galaxies contain mainly old and red stars. The lack of significant star formation in elliptical galaxies suggests that most of the stellar birth and evolution happened early on in their history.

To strengthen this reason, you can investigate the star formation rates of elliptical and spiral galaxies. Astronomers measure star formation rates using various methods such as the detection of specific emission lines or the presence of young, blue stars. It would be helpful to look for studies that have quantified the star formation rates in both types of galaxies.

In summary, elliptical galaxies are considered older and more evolved than spiral galaxies due to their relatively low amounts of interstellar matter and limited star formation rates. To gather more information and support for these claims, you can explore scientific articles and research papers focused on galaxy evolution and stellar populations in different types of galaxies.