The Hubble team has released an incredibly beautiful shot of ACO S 295, a massive galaxy cluster located some 3.5 billion light-years away in the small southern constellation of Horologium.
This image, taken by the NASA/ESA Hubble Space Telescope, shows the massive galaxy cluster ACO S 295. The image is made up of observations from Hubble’s Wide Field Camera 3 (WFC3) and Advanced Camera for Surveys (ACS) instruments in the infrared and optical parts of the spectrum. Seven filters were used to sample various wavelengths. The color results from assigning different hues to each monochromatic image associated with an individual filter. Image credit: NASA / ESA / Hubble / F. Pacaud / D. Coe.
Galaxy clusters contain thousands of galaxies of all ages, shapes and sizes. Typically, they have a mass of about one million billion times the mass of the Sun.
At one point in time they were believed to be the largest structures in the Universe — until they were usurped in the 1980s by the discovery of superclusters.
However, clusters do have one thing to cling on to; superclusters are not held together by gravity, so galaxy clusters still retain the title of the biggest structures in the Universe bound by gravity.
Albert Einstein predicted in his theory of general relativity that massive objects will deform the fabric of space itself.
When light passes one of these objects, such as a massive galaxy cluster, its path is changed slightly.
Known as gravitational lensing, this effect is only visible in rare cases and only the best telescopes can observe the related phenomena.
“The ACO S 295 cluster dominates the center of the new image, both visually and physically,” Hubble astronomers said.
“The huge mass of the galaxy cluster has gravitationally lensed the background galaxies, distorting and smearing their shapes.”
“As well as providing astronomers with a natural magnifying glass with which to study distant galaxies, gravitational lensing has subtly framed the center of this image, producing a visually striking scene.”
“Galaxies of all shapes and sizes populate this image, ranging from stately spirals to fuzzy ellipticals,” the researchers added.
“As well as a range of sizes, this galactic menagerie boasts a range of orientations, with spiral galaxies such as the one at the center of this image appearing almost face on, and some edge-on spiral galaxies visible only as thin slivers of light.”
