COLLEGE STATION, Texas, Aug. 18 (UPI) — Some of the universe’s oldest and most distant clusters of galaxies are still actively forming stars, U.S. astronomers say.
Using NASA’s Spitzer Space Telescope, a team of researchers led by Texas A&M’ University’s Dr. Kim-Vy Tran has discovered a significant fraction of those ancient galaxies are still giving birth to stars, a university release said Wednesday.
Essentially looking back in time nearly 10 billion years at a cluster known as CLG J02182-05102, Tran and her colleagues determined the cluster produces hundreds to thousands of new stars every year, a far higher birthrate than in closer galaxies.
And the stellar birthrate is higher in the cluster’s crowded center than at the its edges — the exact opposite of what happens in our local portion of the universe, where the cores of galaxy clusters are galactic graveyards full of galaxies composed of old stars.
Exactly why this star power increases as galaxies become more crowded remains a mystery, Tran says.
The densely populated surroundings could lead to galaxies triggering activity in one another, or possible all galaxies were extremely active when the universe was younger, she says.
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