The Jellyfish Galaxy JO206 passes through in this image from the NASA/ESA Hubble Space Telescope, displaying a colorful star-forming disk surrounded by a pale, glowing dust cloud. A handful of bright foreground stars with crisscross diffraction spikes stand out against the inky black background at the bottom of the image. JO206 is located 700 million light-years from Earth in the constellation Aquarius.
Jellyfish galaxies are so named because of their similarity to their aquatic namesakes. In the lower right of this image, long tendrils of bright star formation follow JO206’s disk, like jellyfish trail tentacles.
The tendrils of jellyfish galaxies are formed by interactions between galaxies and the intra-cluster medium, a thin superheated plasma that permeates galaxy clusters. As galaxies move through galaxy clusters, they enter the intracluster medium, which pulls gas away from the galaxies and draws them into long tendrils of star formation.
The tentacles of jellyfish galaxies offer astronomers a unique opportunity to study star formation under extreme conditions, far from the influence of the galaxy’s main disk. Surprisingly, Hubble revealed no noticeable differences between star formation in the disks of jellyfish galaxies and star formation in their tentacles, suggesting that the environment of newly formed stars has little effect on their formation.
Image credit: ESA/Hubble & NASA, M. Gullieuszik, GASP Team