This is a section of space near Abell S1063. A galaxy cluster sitting four billion light years away. It makes a great picture by itself. But it’s what Hubble spotted behind the nearby galaxy cluster that is the highlight of the space telescope’s newest picture.
Here’s a picture Abell S1063.
You see the beams of light stretched out? Those are galaxies from behind the massive galaxy cluster. In fact, astronomers say one of them is seen as it was just a billion years after the Big Bang. What you’re seeing is the result of gravitational lensing.
Because Abell S1063 is so massive, it warps the space around it. Light that travels through these areas is amplified through the effect known as gravitational lensing. Imagine a huge cosmic telescope lens.
These galaxies are too distant for Hubble to see it by itself. But with enough gravity to warp the space around it (like a giant galaxy cluster), the galaxies from even further away become visible.
Astronomers have also identified sixteen background galaxies whose light has been distorted by the cluster, causing multiple images of them to appear on the sky. This will help astronomers to improve their models of the distribution of both ordinary and dark matter in the galaxy cluster, as it is the gravity from these that causes the distorting effects. These models are key to understanding the mysterious nature of dark matter.
Abell S1063 is one of several galaxy clusters Hubble uses as a huge lens. According to the Frontier Fields website, these “natural telescopes” allow astronomers to see galaxies that are up to 100 times fainter than any galaxy observed before.
Six galaxy clusters make up the Frontier Fields program.
Astronomers have already conducted observations using four of the enormous galaxy clusters. The remaining two will be observed over the next couple of years.
What’s great about the Frontier Fields Program is we get two great images for the price of one. You see the first image at the top? That’s what astronomers call a “parallel field.”
Hubble’s Wide Field Camera 3 (WFC3) stares at Abell S1063, while the Advanced Camera for Surveys (ACS) looks at a part of the sky nearby. Here’s a diagram showing how this works using Abell 2744 as an example.
The Hubble takes exposures lasting between 15-20 minutes. These are beamed back to Earth and then stitched together to form the stunning images the Hubble team releases to us.
Observations by Frontier Fields makes impressive discoveries like the first predicted appearance of a gravitationally lensed supernova possible. And programs like this one are just the beginning. Soon, the much more powerful James Webb Space Telescope will join other space telescopes in orbit around Earth. And with it, even more distant observations.