The new image of JO204, a spiral galaxy located approximately 600 million light-years away in the constellation of Sextans, was captured by the NASA/ESA Hubble Space Telescope. This is the third of a series of images featuring ram-pressure stripped (jellyfish) galaxies.
Early 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.
It is believed to have a strong impact on galaxy populations in dense environments such as galaxy clusters.
“Given the dreamy appearance of this image of JO204, it would be understandable to wonder why jellyfish galaxies should be such a crucible for star formation,” Hubble astronomers said.
“The answer is that — as is often the case with astronomy — first appearances can be deceiving.”
“Whilst the delicate ribbons of gas beneath JO204 may look like floating jellyfish tentacles, they are in fact the outcome of an intense astronomical process known as ram pressure stripping.”
“Ram pressure is a particular type of pressure exerted on a body when it moves relative to a fluid,” they added.
“An intuitive example is the sensation of pressure you experience when you are standing in an intense gust of wind — the wind is a moving fluid, and your body feels pressure from it.”
“An extension of this analogy is that your body will remain whole and coherent, but the more loosely bound things — like your hair and your clothes — will flap in the wind.”
“The same is true for jellyfish galaxies,” the astronomers said.
“They experience ram pressure because of their movement against the…
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