spaceSpace and Physics

Gravitational-Lensing Galaxy Clusters Reveal Thousands Of New Galaxies We Couldn't Previously See


Dr. Alfredo Carpineti

Senior Staff Writer & Space Correspondent

clockSep 14 2018, 11:29 UTC

The new image of the Abell 370 from the Buffalo Survey. NASA, ESA, A. Koekemoer, M. Jauzac, C. Steinhardt, and the BUFFALO team

The Hubble Frontier Fields observations are some of the most stunning images of six galaxy clusters. These clusters are so massive that they bend space-time and act as a lens, magnifying the light of distant background galaxies that we wouldn't be able to see otherwise.

For many years, researchers have used these galaxy clusters to peer further into the universe’s past than ever before. But it's not enough if we want to have a complete picture of galaxy evolution, so astronomers have increased the efforts and used 101 orbits of Hubble to extend the field of view of these clusters. The first observations have now been released and they show thousands of new galaxies surrounding the Abell 370 cluster (pictured above).


Abell 370 is one of the first galaxy clusters where astronomers observed gravitational lensing. It has been instrumental in studying the early universe, and in 2002 it was used to discover HCM-6A, which was at the time the furthest galaxy ever observed. 


The international project is called BUFFALO – Beyond Ultra-deep Frontier Fields And Legacy Observations – and its main goal is to discover when and how the most massive and luminous galaxies formed. It will also investigate how the formation of early galaxies is linked to dark matter. The focus of the survey is to look at the universe from the first 800 million years after the Big Bang.

“By expanding the area that we map around each of these clusters, we will significantly improve our estimate of the clusters' magnification, a mandatory step for studying the distant galaxies that BUFFALO will discover,” said Dr Mathilde Jauzac, BUFFALO joint lead, and from Durham University's Center for Extragalactic Astronomy, in a statement.


“Plus, BUFFALO will allow us to map precisely the distribution of dark matter in these massive clusters, and thus trace their evolutionary history, a missing piece of information in today's evolution theories.”

BUFFALO is expected to be 10 times more efficient at detecting the most distant galaxies than the original Frontier Fields survey. It will also include the help of other telescopes that have already observed the region around the cluster, allowing researchers a significant amount of data to work with.

The survey will also study the six clusters themselves. Each of them is made up of several hundred galaxies in their cores and by detailing the surrounding fields better, we will learn about the distribution of matter and dark matter within the clusters.


spaceSpace and Physics