National / Science & Health

International team of astronomers discover massive ancient galaxies

JIJI

An international team of astronomers, including those from the University of Tokyo and the National Astronomical Observatory of Japan, have discovered 39 massive galaxies thought to have been actively forming stars over 11 billion years ago.

The galaxies are believed to be the ancestors of massive elliptical galaxies existing now. The discovery is expected to reveal previously unknown details about how the universe and galaxies were formed.

The discovery was published in the online edition of the British science journal Nature on Thursday.

The team, including University of Tokyo professor Kotaro Kono and NAOJ researcher Tao Wang, discovered the galaxies using the Atacama Large Millimeter/submillimeter Array (ALMA) telescope in Chile.

The astronomers initially discovered 63 objects using NASA’s Spitzer Space Telescope that were undetected by the Hubble Space Telescope.

After examining submillimeter-wave emissions using the ALMA telescope, the team found that 39 of the 63 objects were active star-forming galaxies, located over 11 billion light-years away.

In the present universe, they are believed to have become massive elliptical galaxies roughly a trillion times larger than the mass of the sun, according to the astronomers.

No significant theories for the evolution of the universe have predicted such an abundant population of star-forming massive galaxies, the astronomers said.

“We’d like to cooperate with theorists to resolve why there was such a discrepancy (between theory and reality),” Kono said.