The magnificent Hubble Space Telescope has done it again. This week, NASA released the first image from the “Frontier Fields” project where the great telescope, with the help of a giant foreground “gravitational lens”, images objects more than ten times fainter than otherwise possible and records some of the youngest galaxies every seen.
The first image from “Frontier Fields” reveals some 3,000 background galaxies among hundreds of foreground galaxies. The more distant galaxies would not be visible without gravitational lensing of the the Abell 2744 cluster, which bends the light of the more distant galaxies into the Hubble’s line of sight. Most of the bright galaxies in the image at top belong to Abell 2744. But the faint flakes and slivers of light in the image are the far more distant galaxies. The galaxy cluster Abell 2744, also known as “Pandora’s Cluster”, lies in the constellation Sculptor.
As a consequence of gravitational lensing, the galaxies appear some 10 to 20 times larger. They are also 10 to 20 times fainter than any galaxies every observed. The most distant galaxies are seen as they appeared about 12 billion years ago, about 1.6 billion years after the Big Bang and 1.2 billion years after first stars and galaxies formed. The light from the galaxies of Abell 2744 has been traveling towards us for “only” 3.5 billion years.
More about gravitational lenses here: oneminuteastronomer.com/9237/gravitational-lens
Additional images of the six Frontier Fields will be release over the coming months. As well, astronomers will look at these fields in infrared with the Spitzer Space Telescope and in X-rays by the Chandra X-ray observatory to learn more about the formation and evolution of the earliest galaxies.
This short video explains more about NASA’s Frontier Fields project: