JWST Captures Ancient Jellyfish Galaxy

- The research, published in *The Astrophysical Journal*, was led by Dr. Ian Roberts, a postdoctoral fellow at the University of Waterloo. - This galaxy was discovered in a well-studied patch of the sky known as the COSMOS field, which is favored for deep space observations because it is relatively clear of obstructions from the Milky Way's stars and dust. - The finding challenges previous theories that early galaxy clusters were not yet dense or hot enough to cause such extreme ram-pressure stripping, suggesting these harsh galactic environments formed earlier than believed. - In addition to JWST imaging, astronomers used the Gemini Observatory's spectrograph to analyze the trailing tentacles and confirm the presence of an ionized gas tail connected to the galaxy's disk. - The bright blue knots in the galaxy's tail are star-forming regions with stellar populations estimated to be less than 100 million years old. - This observation may help explain the existence of massive, non-star-forming galaxies in the early universe, sometimes called "red nuggets," by providing a direct look at a potential gas-quenching mechanism. - While it is the strongest and most distant candidate found to date, researchers have noted that further observations are needed to officially confirm COSMOS2020-635829 as a jellyfish galaxy.