Galaxy formation and evolution
Silk, Joseph Department of Physics, University of Oxford, Oxford, United Kingdom.
Khochfar, Sadegh Max-Planck-Institute for Extraterrestrial Physics, Garching, Germany.
Last reviewed:February 2019
Show previous versions
- Evidence from structural properties
- Evidence from composition
- Influences of black holes
- Origin of galaxies
- Related Primary Literature
- Additional Reading
How the diverse array of galaxies that are now observed originated and evolved into their present form. Deep telescope observations of the cosmos have found evidence for the first galaxies arising within several hundred million years after the big bang. Since that time more than 13 billion years ago, galaxies have emerged throughout the universe, numbering in the hundreds of billions and often appearing in grand agglomerations known as clusters and in long, vast threads known as filaments. Most galaxies also have evolved to fall into three, broad categories of shape: spiral (with curving internal structures of stars), elliptical (rounded), and irregular (no defined shape) (Fig. 1). Researchers studying galaxy formation and evolution “work backwards” in explaining how galaxies assumed these shapes, predominantly occur in clusters, and have changed as a population over cosmic history. See also: Big bang theory; Cosmology; Galaxy; Universe
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 10,000 highly qualified scientists and 45 Nobel Prize winners.
MORE THAN 8700 articles covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information