Hodge, Paul Department of Astronomy, University of Washington, Seattle, Washington.
Turner, Edwin L. Peyton Hall, Princeton University Observatory, Princeton, New Jersey.
Turner, Joyce B. Princeton University Observatory, Princeton, New Jersey.
Khochfar, Sadegh Max-Planck-Institute for Extraterrestrial Physics, Garching, Germany.
Silk, Joseph Department of Physics, University of Oxford, Oxford, United Kingdom.
- Form and size
- Exotic galaxy types
- Internal motions
- Active nuclei
- Links to Primary Literature
- Additional Readings
One of the large self-gravitating aggregates of stars, gas, and dust that contain a large amount of the visible baryonic matter in the universe. Typical large galaxies have symmetric and regular forms, are about 50,000 light-years (3 × 1017 mi or 5 × 1017 km) in diameter, and are roughly 3 × 1010 times more luminous than the Sun. The stars and other material within a galaxy move through it, often in regular rotation, with periods of a few hundred million years. The characteristic mass associated with a large galaxy is a few times 1012 solar masses. (The solar mass is 4.4 × 1030 lb or 2 × 1030 kg.) Galaxies often occur in groups or clusters containing from a few to many thousands of individual galaxies and ranging in size from a few hundred thousands to tens of millions of light-years. The nearest galaxy to the Milky Way Galaxy, the Sagittarius Dwarf Galaxy, is about 80,000 light-years (4 × 1017 mi or 6 × 1017 km) away; the farthest, more than 1 × 1010 light-years (6 × 1022 mi or 1 × 1023 km). Galaxies are the landmarks by which cosmologists survey the large-scale structure of the universe. See also: Baryon
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. Its dedicated editorial team is led by Sagan Award winner John Rennie. Contributors include more than 9000 highly qualified scientists and 42 Nobel Prize winners.
MORE THAN 8500 articles and Research Reviews 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 17,000 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