By Alex and Shy
How the Galaxy was created
The study of galaxy formation and evolution is concerned with the processes that formed a heterogeneous universe from a homogeneous beginning, the formation of the first galaxies, the way galaxies change over time, and the processes that have generated the variety of structures observed in nearby galaxies.
The Big Bang
Galaxy formation is hypothesized to occur, from structure formation theories, as a result of tiny quantum fluctuations in the aftermath of the Big Bang.
Extra Stuff You Need to Know
- The majority of mass in galaxies is made up of dark matter, a substance which is not directly observable, and might not interact through any means except gravity.
- Many disk galaxies have a puffed up outer disk that is composed of old stars
- Many of the properties of galaxies indicate that there are fundamentally two types of galaxies. These groups divide into blue star-forming galaxies that are more like spiral types, and red non-star forming galaxies that are more like elliptical galaxies.