By Xinhua,
Washington : Using the Hubble Space Telescope, astronomers say they have detected nine young galaxies in the early Universe, packed with improbable numbers of stars, according to a study published Tuesday.
Astronomers looking at galaxies in the Universe’s distant past have discovered these nine galaxies, each weighing in at 200 billion times the mass of the Sun.
The galaxies, about 11 billion light years away, are a fraction of the size of today’s grownup galaxies but contain approximately the same number of stars.
“Seeing the compact sizes of these galaxies is a puzzle,” said Pieter G. Van Dokkum of Yale University, who led the study, in a prepared statement published Tuesday by the Hubble project.
“No massive galaxy at this distance has ever been observed to be so compact.”
It is not yet clear how the galaxies would build themselves up, said Van Dokkum.
Based on the galaxies’ mass, which is derived from their colors, the astronomers estimated that the stars are spinning around their galactic disks at roughly 400 to 500 kilometers per second.
Stars in today’s galaxies, by contrast, are traveling at about half that speed because they are larger and rotate more slowly than the compact galaxies.
The findings also appeared in the latest issue of The Astrophysical Journal Letters.