Thousands of unseen galaxies discovered by scientists in Durham

Astronomers have discovered thousands of unseen galaxies scattered in space and time.

The image of Abell 370 galaxy cluster and its environs was published as part of the "Beyond the Deepest Fields and Heritage Observations" survey conducted by the University of Durham .

BUFFALO, led by Durham and the Niels Bohr Institute in Denmark, is a new study of NASA / ESA's Hubble Space Telescope to expand its vision of largely unexplored regions of the universe.

Several hundred galaxies are visible at Abell 370, located about 4 billion light-years from Earth, at the center of the new image.

Thousands of unseen distant galaxies, located behind Abell 370, are also revealed in the image by an effect called gravitational lens.

The huge mass of clusters of galaxies like Abell 370, mainly composed of mysterious dark matter, bends and magnifies the light of these distant objects, transforming these clusters into natural telescopes.

This gravitational lens effect allows scientists to see farther into the space beyond the cluster, capturing the light emitted by very distant and weak objects.

The most amazing demonstration of the gravitational lens in Abell 370 can be seen just below the center of the cluster.

Nicknamed "The Dragon", this feature is a combination of five gravitational lens images of the same spiral galaxy beyond the group.

Although Hubble has already detected some of the first galaxies in the universe through its Frontier Fields program, these fields are relatively small and may not fully represent the number of early galaxies in the universe at large.

BUFFALO relies on these observations using gravitational lenses and will extend the search area around the six boundary fields previously observed by Hubble.

Abell 370 is the first group to be observed.

BUFFALO will study how and when the most massive and luminous galaxies of the universe were formed and how they are related to the assembly of dark matter.

The survey will also learn about the evolution of clusters of lens galaxies and will provide clues to the nature of dark matter.

The first step is to draw a detailed map of the dark matter mass of these clusters of galaxies to accurately measure the magnification of lens galaxies.

The program will determine how quickly galaxies formed in the 800 million years after the Big Bang – opening the way for observations with NASA / ESA / CSA's upcoming James Webb space telescope.

Dr. Mathilde Jauzac, co-leader of BUFFALO at the Center for Extragalactic Astronomy at the University of Durham, said: "By expanding the area we map around each of these groups, we will vastly improve our galaxy estimate distant that BUFFALO will discover.

"In addition, BUFFALO will allow us to precisely map the distribution of dark matter in these massive clusters and to trace their evolutionary history, a missing piece of information in today's evolutionary theories.

"BUFFALO represents a great opportunity to understand how dark matter assembles, interacts and evolves in the most massive structures present in our universe."

In addition to using Hubble, BUFFALO will also take advantage of observations from other space telescopes, including very deep Spitzer Space Telescope observations that already exist around these groups.