BY: Arjit Mishra
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Superficially there are four categories to classify Galaxies: Spiral; Barred Spiral; Elliptical and Irregular.
Elliptical Galaxies have a smooth ellipsoidal morphology, They are mostly found in Galaxy Clusters.
One of the notable feature of an elliptical galaxy is that they naturally contain a much greater proportion of older stars than spiral galaxies do.
Nowadays Astronomers Theorize that most of the elliptical galaxies are formed from the collisions and subsequent mergers of spiral galaxies. Ages and Complexion of Stellar population holds evidence for this theory, because the stars in elliptical galaxies are much older and redder than those in spiral galaxies.
Moreover spiral galaxies have abundant gas and dust which eventually fuels Star formation, whilst elliptical galaxies appear to have virtually exhausted that fuel and so there is scarcity of raw material for the formation of new stars. Due to this low rate of star formation and their populations of old, red stars, elliptical galaxies are referred to as 'RED and DEAD' by Astronomers.
Obviously with the help of Hubble and ESO'S VLT(Very Large Telescope) Astronomers were able to show how star formation in these DEAD- Galaxies actually took place billions of years ago and practically prove the theory.
"ONLY IN DARKNESS CAN YOU SEE THE STARS"
Nice Explanation
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