In 2005, the Hubble Space Telescope found unusually small galaxies densely packed with red stars in the distant, young universe because they are small and red and also as their existence challenged current theories of galaxy formation, making them precious in astronomers' eyes.
Since no "red nuggets" were seen nearby, astronomers used to wonder why they had disappeared over time.
New research shows that they didn't disappear completely and in fact were simply hidden within the data of previous surveys.
To find them, astronomer Ivana Damjanov (Harvard-Smithsonian Center for Astrophysics) and her colleagues searched databases from the Sloan Digital Sky Survey.
The "red nugget" galaxies are so small that they appear like stars in photographs from ground-based telescopes. However, their spectra give away their true nature.
By sifting through the Sloan data, the team dug up more than 600 "red nugget" candidates. They are located at distances of 2.5 to 5.7 billion light-years from Earth.
Damjanov then investigated the Hubble Space Telescope database to find photos of the patches of sky where those objects were located. Serendipitous images of nine targets confirmed that they are as compact as more distant "red nugget" galaxies.
The most massive weigh up to 10 times more than the Milky Way, but are up to 10 times smaller than our galaxy. As a result, they're called compact, massive galaxies.
--ANI (Posted on 14-09-2013)