Astronomers using the Hubble Space Telescope (NASA/ESA) observed star formation clumps in the tails and disks of six jellyfish galaxies.
Understanding the physical conditions that lead to the formation of new stars and, conversely, to the cessation of star formation activity, is central to astrophysics.
The disks of galaxies are the cradle of star formation, a process that is ubiquitous in galaxies.
Very distant galaxies are dominated by bright clumps of star formation that are larger and more massive than galaxies in the local universe.
Star formation activity is strongly influenced by a number of processes, some of which are directly related to the environment in which the galaxy resides.
The removal of interstellar gas from the disk of star-forming galaxies, due to hydrodynamic interaction with the hot intergalactic medium, is one such process and is thought to have a strong influence on star formation processes.
“As the jellyfish galaxies move through intergalactic space, they are slowly shedding the gas that trails behind the galaxy in the form of tendrils, illuminated by clumps of star formation,” said Dr. Marko Gullieusik of INAF.
These blue appendages are visible under the galaxy’s core in the Hubble image and give it the appearance of a jellyfish.
This particular jellyfish galaxy, known as JO201, lies in the constellation Cetus, which is named after a sea monster from ancient Greek mythology.
This constellation in the form of a sea monster complements the nautical theme of the image.
In their study, the astronomers used Hubble to study star formation clumps in JO201 and five other jellyfish galaxies.
They found more than 3700 clumps in disks, 1200 clumps in out-of-plane regions and more than 1200 clumps in the tails of these galaxies.
Only 15% of the star formation clumps have been spatially resolved, meaning that most of them are less than 500 light-years across.
The star-forming regions in the striped tails are extremely bright and compact.
The findings are published in two articles in Astrophysical Journal.