Universe 

Astronomers Uncover a Surprising Trend in Galaxy Evolution

A comprehensive study of hundreds of galaxies observed by the Keck telescopes in Hawaii and NASA's Hubble Space Telescope has revealed an unexpected pattern of change that extends back 8 billion years, or more than half the age of the universe.

"Astronomers thought disk galaxies in the nearby universe had settled into their present form by about 8 billion years ago, with little additional development since," said Susan Kassin, an astronomer at NASA's Goddard Space Flight Center in Greenbelt, Md., and the study's lead researcher. "The trend we've observed instead shows the opposite, that galaxies were steadily changing over this time period."

Today, star-forming galaxies take the form of orderly disk-shaped systems, such as the Andromeda Galaxy or the Milky Way, where rotation dominates over other internal motions. The most distant blue galaxies in the study tend to be very different, exhibiting disorganized motions in multiple directions. There is a steady shift toward greater organization to the present time as the disorganized motions dissipate and rotation speeds increase. These galaxies are gradually settling into well-behaved disks.

Blue galaxies — their color indicates stars are forming within them — show less disorganized motions and ever-faster rotation speeds the closer they are observed to the present. This trend holds true for galaxies of all masses, but the most massive systems always show the highest level of organization.

Researchers say the distant blue galaxies they studied are gradually transforming into rotating disk galaxies like our own Milky Way.

Watch this video on YouTube.


For More Information

http://www.nasa.gov/topics/universe/features/galaxy-evol.html


Credits

Scott Wiessinger (USRA): Lead Animator
Chris Meaney (HTSI): Animator
Scott Wiessinger (USRA): Video Editor
Susan Kassin (ORAU): Interviewee
Scott Wiessinger (USRA): Narrator
Scott Wiessinger (USRA): Producer
Susan Kassin (ORAU): Scientist
Scott Wiessinger (USRA): Videographer
Genna Duberstein (USRA): Videographer
Francis Reddy (Syneren Technologies): Writer
Please give credit for this item to:
NASA/Goddard Space Flight Center. However, individual images should be credited as indicated above.

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Mission:
James Webb Space Telescope - JWST

This item is part of these series:
Narrated Movies
Astrophysics Simulations
Astrophysics Stills
Astrophysics Features

Goddard TV Tape:
G2012-084 -- Galaxy Evolution Patterns

Keywords:
SVS >> Galaxy
SVS >> HDTV
SVS >> Milky Way
SVS >> Music
SVS >> Simulation
SVS >> Hubble Space Telescope
SVS >> Astrophysics
SVS >> Universe
SVS >> Edited Feature
SVS >> Space
SVS >> Interview
DLESE >> Narrated
SVS >> James Webb Space Telescope
NASA Science >> Universe