Starship Asterisk*

VLT Survey Telescope Captures the Fornax Cluster
[imghover=https://cdn.eso.org/images/screen/eso1612a.jpg]https://cdn.eso.org/images/screen/eso1612b.jpg[/imghover]Credit: ESO. Acknowledgement: Aniello Grado and Luca Limatola[hr][/hr]

This new image from the VLT Survey Telescope (VST) at ESO’s Paranal Observatory in Chile captures a spectacular concentration of galaxies known as the Fornax Cluster, which can be found in the southern hemisphere constellation of Fornax (The Furnace). The cluster plays host to a menagerie of galaxies of all shapes and sizes, some of which are hiding secrets.

Galaxies, it seems, are sociable animals and they like to gather together in large groups, known as clusters. Actually it’s gravity that holds the galaxies in the cluster close together as a single entity, with the pull of gravity arising from large amounts of dark matter, as well as from the galaxies we can see. Clusters can contain anything between about 100 and 1000 galaxies and can be between about 5 and 30 million light-years across.

Galaxy clusters do not come in neatly defined shapes so it is difficult to determine exactly where they begin and end. However, astronomers have estimated that the centre of the Fornax Cluster is in the region of 65 million light-years from Earth. What is more accurately known is that it contains nearly sixty large galaxies, and a similar number of smaller dwarf galaxies. Galaxy clusters like this one are commonplace in the Universe and illustrate the powerful influence of gravity over large distances as it draws together the enormous masses of individual galaxies into one region. ...

• Astrophysical Journal 820(1):42 (2016 Mar 20) DOI: 10.3847/0004-637X/820/1/42
  arXiv.org > astro-ph > arXiv:1602.02149 > 05 Feb 2016

bystander wrote:
Inside the Fiery Furnace
ESO Photo Release | VST | 2016 Apr 13

Galaxies, it seems, are sociable animals and they like to gather together in large groups, known as clusters.