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Taiwan-US astronomers shed light on 'dusty galaxies'

The Submillimeter Array, which contains eight radio antennas, is located at the Mauna Kea Observatory in Hawaii. (Courtesy of Wang Wei-hao)

• Publication Date：12/22/2010
• Source： Taiwan Today

Recent findings by a Taiwan-U.S. observation team studying distant “dusty galaxies” could lead to a revision of astronomers’ understanding of these ancient stellar phenomena.

The team led by Wang Wei-hao, a research fellow at Academia Sinica’s Institute of Astronomy and Astrophysics, discovered that earlier identifications of these galaxies were likely incomplete and failed to show further hidden galaxies.

Using an upgraded Submillimeter Array, the team found five dusty galaxies in two sectors where it had initially expected only to find two, Wang said Dec. 21. This led researhcers to postulate that the total number of such galaxies might be more than astronomers had previously believed.

Dusty galaxies, which existed in the early universe, were several thousand times more luminous than our Milky Way but are difficult to observe because they are obscured by cosmic dust. The first observations of such galaxies were by a U.S.-U.K. team in 1997.

According to scientists, because of their great distance from the Earth, the dusty galaxies people see are as they appeared only two to six billion years after the Big Bang, which occurred roughly 14 billion years ago, during a period of great stellar activity.

Wang said the team’s findings could lead to revisions of established astronomical knowledge that has been accumulated over 400 years since Galileo’s improvements to the telescope.

He added that the research will help scientists gain more understanding on events happened in the period after the Big Bang. For example, why so many stars formed at that time and how they formed, he said.

The results of the team’s observations were published in the international journal “The Astrophysical Journal Letters” Dec. 16. (SB)