Astronomers using the NASA/ESA Hubble Space Telescope have observed clumps of star formation in the tails and disks of six ram-pressure stripped (jellyfish) galaxies.
Understanding the physical conditions that lead to the formation of new stars, and conversely to the halting of the star formation activity, is central for astrophysics.
Galaxy disks are the usual cradle for star formation. This is a hierarchical process traced by star-forming regions, dubbed clumps, which are ubiquitous in star-forming galaxies.
Extremely distant galaxies are dominated by bright clumps, which are larger and more massive than in the local Universe.
The star formation activity is strongly influenced and can be even halted by a number of processes, some of which are directly related to the environment in which the galaxy resides.
Ram pressure stripping, i.e. the removal of interstellar gas from the disk of star forming galaxies due to the hydrodynamical interaction with the hot intergalactic medium, is one such process and it is believed to have a strong impact on galaxy populations in dense environments such as galaxy groups and, especially, clusters.
“As jellyfish (ram-pressure stripped) galaxies move through intergalactic space they are slowly stripped of gas, which trails behind the galaxy in tendrils illuminated by clumps of star formation,” said Dr. Marco Gullieuszik from the INAF-Osservatorio astronomico di Padova and colleagues.
“These blue tendrils are visible drifting below the core of a galaxy in the Hubble image, and give it its jellyfish-like appearance.”
“This particular jellyfish galaxy — known as JO201 — lies in the constellation Cetus, which is named after a sea monster from ancient Greek mythology.”
“This sea-monster-themed constellation adds to the nautical theme of the image.”
In their study, the astronomers used Hubble to study star-forming clumps in JO201 and five other jellyfish galaxies.
They detected over 3,700 clumps in the disks,…
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