On the occasion of the new year, employees of the NOIRLab science center published a very spectacular image taken by the Dark Energy Camera (DECam). It shows lots of sparkling galaxies in the Antlia Cluster.
Clusters of galaxies are some of the largest structures in the Universe. According to existing models, they are formed under the action of dark matter, whose gravity pulls together groups of galaxies, forming conglomerates consisting of hundreds or even thousands of members.
One of the closest such groups to us is the Antlia Cluster, located 130 million light-years away from Earth toward the constellation of the same name. We see it in this DECam image. The 570-megapixel camera captured part of the cluster’s 230 galaxies. Thousands of more distant background galaxies also got into the picture.
The Antlia Cluster is dominated by two massive elliptical galaxies, NGC 3268 (center) and NGC 3258 (bottom right). They are surrounded by a number of dim dwarf galaxies. Based on X-ray observations, the researchers believe the two galaxies are in the process of merging. This may be evidence that the Antlia Cluster is actually made up of two smaller clusters that merge.
The Antlia Cluster is rich in lenticular galaxies. This is the name given to galaxies occupying an intermediate position between spiral and elliptical galaxies. They still retain disk structure, but contain little gas and almost no new star formation. Many rare low-luminosity dwarf galaxies have also been found in the cluster, including ultra-compact dwarfs, compact elliptical galaxies, and blue compact dwarfs. Dwarf spheroidal galaxies and ultra diffuse galaxies may also be present in the cluster, although further studies are needed to confirm them.
Many of these types of galaxies have only been identified in the last few decades due to the development of large and highly sensitive cameras such as DECam and the development of new methods of data analysis. Evaluating galaxy types allows astronomers to learn new details about their structure and better understand the impact of dark matter on the evolution of the Universe.
According to NOIRLab
