UQ Media Release 2003 May 29

Scientists confirm presence of new class of galaxy

Summary: A major international research effort has discovered a new type of very small galaxy, known as an "ultra-compact dwarf galaxy" (UCD).

The galaxies are so compact that astronomers previously mistook them for nearby stars in galaxy censuses based on large, ground-based pictures taken of the sky.

The finding, reported today in Nature, was made by a team of eight astrophysicists from Australia, the U.S., Germany, and the U.K.

Project team leader, UQ Senior Lecturer in Physics Dr Michael Drinkwater, said the discovery confirms a suspicion that has been troubling astronomers for over 25 years.

"There has always been the concern that galaxy surveys are biased against finding very diffuse galaxies, because they are so faint, and very compact galaxies, because they look just like stars", he said.


Other reports of this work

  1. The Sydney Morning Herald (29/5)
  2. The Canberra Times (30/5)
  3. The Age (30/5)
  4. The Townsville Bulletin (30/5)
  5. The Gold Coast Bulletin (30/5)
  6. The Sunshine Coast Daily (30/5)
  7. The Gympie Times (30/5)
  8. The Daily News Tweed Heads (30/5)

Download Images

  1. Main press release image from above

    Low resolution (356x504 jpg 220kb)
    Medium resolution (1275x1805 jpg 360kb)
    High resolution (2550x3610 jpg 7.8Mb)

    High resolution background image (tif 8Mb)

    Caption: The Fornax Cluster of galaxies with insets, 60-times magnified, of a normal dwarf galaxy (upper) and a newly-discovered "ultra-compact dwarf" (UCD) galaxy (lower). A simulation of the remains of a a normal dwarf galaxy after disruption to form a UCD is shown in the centre.
    Credits: Insets: Hubble Space Telescope; background Michigan Curtis Schmidt Telescope and Arna Karick (University of Melbourne).

  2. Animation of how we think UCDs formed

    Animation file (windows, 40MB, please contact Michael Drinkater for this file)

    Credits: Dr. Kenji Bekki, University of New South Wales, Sydney

  3. Images of Michael Drinkwater

    cover cover

    Credits: UQ Communications/European Southern Observatory (background)

Telescopes used in this work

The Hubble Space Telescope (NASA)
The Very Large Telescope (European Southern Observatory)
The 2.5-meter (100-inch) Irénée du Pont telescope at Las Campanas Observatory (Carnegie Institution of Washington)
The galaxies were originally discovered with the 3.9-metre Anglo-Australian Telescope.

Last modified: 2004 March 31; Created: 2003 May 22; Maintained by: Michael Drinkwater; Email: mjd @ physics uq edu au
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