2008-07-11 02:24:15 GMT 2008-07-11 10:24:15 (Beijing Time) Xinhua English
A galaxy 12.3 billion light years away from the Milky Way, nicknamed "Baby Boom", is seen in this undated handout image released to Reuters July 10, 2008. Telescopes looking back in time to more than 12 billion years ago have spotted a star factory -- a galaxy producing so many new stars that they have nicknamed it the "baby boom" galaxy. (Xinhua/Reuters Photo)
WASHINGTON, July 10 (Xinhua) -- A team of astronomers have uncovered an extreme stellar machine -- a galaxy in the very remote universe pumping out stars at a surprising rate of about 1,000 to 4,000 per year, NASA reported on Thursday.
At that rate, the galaxy needs only 50 million years, not very long on cosmic timescales, to grow into a galaxy equivalent to the most massive ones we see today.
"In comparison, our own Milky Way galaxy turns out an average of just 10 stars per year," said NASA in a press release.
While galaxies in our nearby universe can produce stars at similarly high rates, the farthest one known before now was about 11.7 billion light-years away. However, the exact distance to this galaxy is a whopping 12.3 billion light-years.
This new discovery, made possible by several telescopes including NASA's Spitzer Space Telescope, goes against the most common theory of galaxy formation. According to the theory, called the Hierarchical Model, galaxies slowly bulk up their stars over time by absorbing tiny pieces of galaxies -- and not in one big burst as observed in the newfound "Baby Boom" galaxy.
"This galaxy is undergoing a major baby boom, producing most of its stars all at once," said Peter Capak of NASA's Spitzer Science Center, who is lead author of a new report detailing the discovery in the July 10th issue of Astrophysical Journal Letters.
The Baby Boom galaxy, which belongs to a class of galaxies called starbursts, is the new record holder for the brightest starburst galaxy in the very distant universe, with brightness being a measure of its extreme star-formation rate.
This is because it has a huge number of youthful stars. When stars are born, they shine with a lot of ultraviolet light and produce a lot of dust. The dust absorbs the ultraviolet light but, like a car sitting in the sun, it warms up and re-emits light at infrared and submillimeter wavelengths, making the galaxy unusually bright to the observing telescopes.