Intracluster light is a diffuse glow of stars stripped of galaxies when the formation of a galaxy cluster.
Abell 3667 is presented in this Decam image. Image Credit: CTIO / NORALLAB / NSF / AURA / Anthony Englert, Brown University / TA RECORT, University of Alaska Anchorage & NSF’s NIGHLAB / M. ZAMANI & D. DE MARTIN, NSF’s Noirlab.
Galaxies clusters contain thousands of galaxies of all ages, shapes and sizes.
As a rule, they have a mass of about a million billion times the mass of the sun.
At one point, the clusters of galaxies were considered the largest structures in the universe – until they were usurped in the 1980s by the discovery of superclusters, which generally contain dozens of clusters of galaxies and groups and cover hundreds of millions of light years.
However, the clusters have something to hang on; Superclusters are not maintained together by gravity, so the clusters of galaxies still retain the title of the largest structures in the universe linked by gravity.
“The stories of the clusters of galaxies not only help us to understand how the universe has formed, but they also provide constraints on the properties of dark matter,” said astronomer at Brown Anthony Englert University and his colleagues said in a press release.
An index that astronomers are looking for to understand the story of a group of galaxies is intracluster light – the slight glow emitted by stars that have been eliminated from their original galaxies by the immense gravity of a forming galaxy cluster.
These stars serve as whispered evidence of past galactic interactions, although most telescopes and existing cameras are fighting to capture them.
The delicate intraclusk light of Galaxy Cluster Abell 3667 shines prominently in the new image assembled from a total of 28 hours of observations with the black energy camera of 570 megapixels (Decam) on the telescope of 4-M Víctor M. Blanco de NSF at the inter-American observatory of Cerro Tololo, a Blacklab program of NSF.
“Abell 3667 is more than 700 million light years of us,” said astronomers.
“The vast majority of small light sources in this image are very distant galaxies, and not the leading stars in our own galaxy of the Milky Way.”
“In Abell 3667, two small clusters of galaxies actively merge, as evidenced by the brilliant (yellow) bridge of the stars extending through the center of this image.”
“This bridge connects the heart of the two clusters of galaxies, known as their brightest cluster galaxies, and are formed from materials eliminated from galaxies when they merge to form a solid conglomerate.”
“Not only is this glitter sky full of distant galaxies, but the leading characteristics are also lit by its long exposure time.”
“Cirrus in the milky way, or the nebula of integrated flows, are low and defeated interstellar dust clouds which can be considered as light bluish strands crisscrosing the image.”
“These Cirrus are dust plates illuminated by the combined light of stars in our own galaxy.”
“They appear as diffuse stringy structures which can cover large areas of the sky.”
The results appear in the Astrophysical newspaper letters.
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Anthony M. Englert and al. 2025. The intracluster light of Abell 3667: reveal an optical bridge in the LSST precursor data. Apjl 989, L2; DOI: 10.3847 / 2041-8213 / ADE8F1
