Galaxy Cluster Abell 2813 has so much mass that it acts as a gravitational lens

Abell 2813, a massive galaxy cluster, has so much mass that it acts as a gravitational lens, causing light from more distant galaxies to bend around it. Thousands of galaxies of various ages, shapes, and sizes can be found in galaxy clusters. They typically have a mass one million billion billion times that of the Sun.

A stunning new Hubble Space Telescope image shows SPT-CL J0615-5746, a massive group of galaxies located approximately 7.7 billion light-years away in the constellation Pictor. SPT-CL J0615-5746, discovered less than a decade ago by the South Pole Telescope, is so massive that its gravity bends light like a lens, making it ideal for peering deep into the early Universe.

A huge galaxy cluster called Abell 2813 has so much mass that it acts as a gravitational lens, causing light from more distant galaxies to bend around it.

Galaxy clusters were once thought to be the largest structures in the Universe — until the discovery of superclusters in the 1980s, which typically contain dozens of galaxy clusters and groups and span hundreds of millions of light-years. However, clusters have one advantage: superclusters are not held together by gravity, so galaxy clusters continue to be the largest structures in the Universe bound by gravity.

Thousands of galaxies of various ages, shapes, and sizes can be found in galaxy clusters. They typically have a mass of one million billion billion times that of the Sun and form over billions of years as smaller groups of galaxies slowly collide. In his general theory of relativity, Albert Einstein predicted that massive objects would deform the fabric of space itself. When light passes through one of these objects, such as a massive galaxy cluster, its path is slightly altered. This effect, known as gravitational lensing, is only visible in rare cases, and the related phenomena can only be observed with the best telescopes. A galaxy cluster called SPT-CL J0615-5746 is one of the farthest observed to cause gravitational lensing.

Hubble Sees Lensing Galaxy Cluster Abell 2813

In his general theory of relativity, Albert Einstein predicted that massive objects would deform the fabric of space itself. When light passes through one of these objects, such as a galaxy cluster, its path is slightly altered. This effect, known as gravitational lensing, is only visible in rare cases and can only be observed with the best telescopes.

Abell 2813, a galaxy cluster in the constellation Cetus, is depicted in a new Hubble Space Telescope image. It is so far away that light from it has traveled for approximately 3.4 billion years to reach us. It is also known as ACO 2813 and RXC J0043.4-2037.

Abell 2813’s gravity acts as the aforementioned gravitational lens, allowing us to see the more distant galaxies sitting behind them. “Among the tiny dots, spirals, and ovals that are the cluster’s galaxies, there are several distinct crescent shapes,” Hubble astronomers said. “These curved crescents and s-shapes of light are not from curved galaxies, but rather from galaxies beyond Abell 2813.”

“The light from distant objects travels to us from such a great distance that it takes an enormous amount of time to reach us, implying that it carries information from the past — information about the time at which it was emitted.”

Gravitational lensing occurs when the mass of an object bends light. The curved crescents and s-shapes of light in this image are not from curved galaxies, but rather from galaxies beyond Abell 2813. Because the galaxy cluster is so massive, it acts as a gravitational lens, bending light from more distant galaxies around it. These distortions can take many forms, such as long lines or arcs.

On July 16, 2009, Hubble’s Advanced Camera for Surveys (ACS) in Wide Field mode captured these images. The composite image was created by isolating light from the green, red, and infrared wavelengths using filters. The Hubble Servicing Mission 4 Early Release Observations include these Hubble data.