Galaxy A1689-zD1 is an ancient galaxy and is so far from Earth that astronomers see the family of stars as it existed in the earliest days of galactic formation in the universe. Most galaxies from this ancient age show little star formation, but the process is highly-active in this dusty grouping.
Cosmic dust, composed of carbon, oxygen, iron, silicon, magnesium and other elements, is often seen in older galaxies, but most infant galaxies are largely devoid of the materials. These elements are forged deep in the cores of stars, before being distributed to space. Once there, these atoms can seed the formation of new generations of stars. Astronomers traditionally believed galaxies would have to go thorough several generations of stars before cosmic dust built up to the concentrations seen in the distant family of stars.
A gravitational lens is formed by a cluster of galaxies known as Abell 1689, which sits between the Earth and the ancient galaxy. Gravity from the grouping of stars bends light like a lens, acting as a telescope, magnifying the image of the galaxy by more than nine times - roughly the same as a powerful pair of binoculars.
The X-shooter instrument at the Very Large Telescope in Chile was used to image the galaxy, revealing the large amount of cosmic dust present in the family of stars.
Light takes a certain amount of time to reach earth from a distant object. The galaxy A1689-zD1 is so distant that astronomers are seeing the family of stars as it was when the universe was only five percent of its current age, just 700 million years after the big bang.
"Although the exact origin of galactic dust remains obscure, our findings indicate that its production occurs very rapidly, within only 500 million years of the beginning of star formation in the Universe -- a very short cosmological time frame, given that most stars live for billions of years," Darach Watson from the University of Copenhagen said.
Astronomers believe dust within the body could be accounted for if the galaxy formed stars at a constant rate since 560 million years after the big bang, or if an extreme period of stellar formation, known as a star burst, was followed by a decline of stellar births.
"This amazingly dusty galaxy seems to have been in a rush to make its first generations of stars. In the future, ALMA will be able to help us to find more galaxies like this, and learn just what makes them so keen to grow up," Kirsten Knudsen, of Chalmers University of Technology in Sweden, said.
As light from the distant body traveled toward earth, the expansion of the universe stretched wavelengths of electromagnetic radiation to lower frequencies.
The Atacama Large Millimeter Array (Alma) and Hubble Space Telescope had previously imaged the distant, dusty galaxy, but details of its composition were not apparent to astronomers.
