The appearance of the galactic jellyfish is one of the most extraordinary and unusual occurrences in the universe. In its natural form, it appears like a captivating, brilliant purple and blue, glowing creature floating in the depths of space. This anomaly has been the cause of both intrigue and confusion for astronomers for centuries.
What is it? Basically, jets of star-forming gas. And they drip from the disk of the JW100 galaxy like streaks of fresh paint. These are formed by a process called drag pressure stripping. They also explain the appearance of the galactic jellyfish.
Its resemblance to dangling tentacles led astronomers to refer to JW100 as a “jellyfish” galaxy. JW100 lies more than 800 million light-years away in the constellation Pegasus. It appears at lower right in this NASA/ESA Hubble Space Telescope image.
Drag pressure stripping occurs when galaxies encounter the diffuse gas that invades galaxy clusters. What happens when galaxies pass through this tenuous gas? It acts like a headwind, ripping gas and dust away from the galaxy. It creates the trailing streamers that adorn JW100. The bright elliptical blobs in the image are other galaxies in the cluster that hosts JW100, NASA reports.
Toward the top of this image are two bright spots. They are surrounded by a remarkably bright area of diffuse light. This is the nucleus of IC 5338, the brightest galaxy in the cluster. IC 5338 is an elliptical galaxy with an extended halo, a type of galaxy called a cD galaxy. These galaxies probably grow by consuming smaller galaxies. Therefore, it is not uncommon for them to have multiple cores. Their cores can take a long time to be absorbed. The bright points of light that stud the outer edges of the galaxy are a rich population of globular star clusters.
This observation took advantage of the capabilities of Hubble’s Wide Field Camera 3. The data are part of a sequence of observations. They were designed to explore star formation in the tendrils of medusa galaxies. These tendrils represent star formation under extreme conditions. They could help astronomers better understand the star formation process in other parts of the universe. The appearance of the galactic jellyfish could precede the appearance of others.