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A Monster Galaxy in the Early Universe

An international team led by Bunyo Hatsukade of the Univsersity of Tokyo and Daisuke Iono of the Nobeyama Radio Observatory revealed detailed properties of SXDF850.6, a galaxy found in the early universe, by using seven telescopes around the world and an infrared space telescope: Atacama Submillimeter Telescope Experiment (ASTE), Subaru Telescope, Submillimeter Array (SMA), James Clerk Maxwell Telescope (JCMT), Very Large Array (VLA), United Kingdom Infra-Red Telescope (UKIRT), Cerro Tololo Inter-American Observatory (CTIO) 4-m telescope, and the Spitzer Space Telescope. They investigated the energetics of SXDF850.6 at a wide range of wavelengths from ultra-violet to radio and found that it is creating more than a thousand stars per year in the universe only a few billion years old.

Because of its extreme star formation properties, astronomers refer to these types of galaxies as "monster galaxies". This particular monster galaxy appears to have numerous "old" stars in addition to the "newly-born" stars.The team estimates that SXDF850.6 harbors about 250 billion old (Sun-like) stars.

It is thought that star formation in these massive galaxies in the early universe are triggered by collisions and mergers of galaxies. The end product of this dynamic event is thought to be an elliptical galaxy. (Hatsukade et al. 2010, ApJ, 711, 974)

Infrared image of SXDF850.6