New sky surveys reveal that the early universe bustled with "promiscuous" galaxies, black holes hide in galactic glare, and a star burns with unprecedented coolness.
The surveys are opening up new windows into the history and complexity of the universe—and, in some cases, pointing out blind spots in our understanding of the way things work. The discoveries were announced yesterday at a meeting of the American Astronomical Society in Austin, Texas.
Go-Go Galaxies
In its early days the universe was something of a nightclub, full of bright young things merging with wild abandon, says astronomer Shardha Jogee from the University of Texas at Austin.
Now, at middle age, it seems the party's winding down.
Jogee has been using space telescopes to observe galaxy evolution at earlier time periods than ever before.
Improvements in telescopes are allowing us to see further back in time. Since light from distant regions can take millions or billions of years to reach Earth, the events we see in images of these regions actually took place long ago.
These earlier views have shown that when the universe was only about two billion years old, 40 percent of galaxies were merging, Jogee said. Today that figure has dropped to 10 percent.
"This is basically telling you that you have fewer parties as the universe reaches midlife," she said.
(Related: "Faint 'Teenage' Galaxies Found in Early Universe" [November 29, 2007].)
Cool Brown Dwarf
Stephen Warren, an astronomer at Imperial College London, described findings that go beyond what the eye can see.
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