Galaxies

GALAXIES:

By Aditya Arolkar and Daniel Do

What is a Galaxy? //A Galaxy is a massive system that is made up of stars, and stellar remnants, an interstellar medium of gas dust, and an important, but little understood component known as dark matter. The entire system is bound by a massive gravitational force.//

//How is a galaxy formed?// //Before explaining how a galaxy is formed, the fact that all galaxies were formed at approximatly the same time ( 1.3 Billion years ago) should be noted.//

//What types of galaxies are there?//

//Elliptical: A elliptical galaxy has an allipsoidal shape and has little, or no angular movement. Normally elliptical galaxies have very little or no interstellar matter at all.//

//Spiral: A spiral galaxy will usually be made up of two major parts. A large flat disk which contains a lot of interstellar matter, and an ellipsoidally formed bulge part, which contains mostly old stellar population wihtout interstellar matter.// //Lenticular: A lenticular galaxy is a spiral galaxy without a spiral structure. They are smooth disk galaxies where formation has stopped.//

//Irregular: A irregular galaxy is often formed due to distortion from the gravitational field of thier intergalactic neighbours. These galaxies have very peculiar shapes, and a subclass fo distorted disks frequently occur.//

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