Tuesday, July 04, 2006

Developing galaxy an under-luminous blob

On occasion it is fun to look outward to the stars and far beyond - today's story is about ever-developing galaxies.

According to press materials, ESO's VLT has helped scientists to discover a large primordial 'blob', more than 10 billion light-years away. The most likely scenario to account for its existence and properties is that it represents the early stage in the formation of a galaxy, when gas falls onto a large clump of dark matter.

[ESO is the intergovernmental European research organisation for Astronomy in the Southern Hemisphere. It is supported by Belgium, Denmark, Finland, France, Germany, Italy, the Netherlands, Portugal, Sweden, Switzerland and the United Kingdom. VLT stands for very large telescope.]

Over the last few years, astronomers have discovered in the distant Universe a few so-called 'blobs'. These are rather energetic but under-luminous objects, of the size of or much larger than our Milky Way galaxy. Their exact nature is still unclear and several scenarios have been proposed to account for their existence.

An international team of astronomers have discovered a new 'blob' located at a distance of 11.6 billion light-years. It is thus seen as it was when the Universe was only 2 billion years old, or less than 15 percent its present age. The newly discovered object is located in the well-studied GOODS South field.

The blob is twice as big as our Milky Way and the total energy emitted is equivalent to that of about 2 billion suns. Despite this, the object is invisible in the images taken with various telescopes observing from the infrared to the X-ray wavebands, making it a very peculiar object. It is also the only such object found by the astronomers in their survey.

The research has been presented in a Letter to the Editor in the journal Astronomy and Astrophysics. To see spectacular photos visit this site.