SSS 2008-07-17(在线收听) |
This is Scientific American's 60-Second Science,I'm Steve Mirsky,got a minute? Our Milky Way galaxy produces only about 10 new stars annually. But a galaxy far, far away is experiencing a major baby boom. It’s pumping out up to 4,000 new stars a year, and should become a massive elliptical galaxy. The discovery was announced in the July 10th issue of Astrophysical Journal Letters. The Baby Boom galaxy stood out because of its extreme brightness, a function of all its youthful stars. That star-making actually happened 12.3 billion years ago—that’s how long it took for the light to reach us. And the universe was virtually a baby itself, only about 1.4 billion years old, when the Baby Boom galaxy activity happened. Astronomers don’t know if this is an exceptional case or if most massive elliptical galaxies actually formed so early in the universe’s history. The discovery also challenges the accepted model for galaxy formation, which has most galaxies slowly bulking up by absorbing pieces of other galaxies, rather than growing internally. Looks like the new finding will be keeping astronomers busy into old age. Thanks for the minute,for Scientific American's 60-Second Science,I'm Steve Mirsky |
原文地址:http://www.tingroom.com/lesson/sasss/2008/7/98847.html |