James Webb telescope detects a jellyfish galaxy wandering through space

Astronomers using the «James Webb» telescope have discovered a rare jellyfish-like galaxy in deep space.

Jellyfish are galaxies that have long tails of gas and young stars that form and stretch out under the influence of external pressure. The discovered galaxy is located at a distance of 12 billion light years from Earth. The light from the object, called COSMOS2020-635829, has been traveling to us for about 8 billion years. The galaxy was discovered by astronomer Ian Roberts of the University of Waterloo, looking at images taken by «James Webb».

On the way to centers of dense galactic clusters spiral galaxies encounter streams of hot gas that fill the rarefied intergalactic space. As they move, these streams capture gas and stars inside the galaxy, which form a long plume. It is in these tails that new stars form.

After analyzing the image, the researchers found a symmetrical stellar disk with a one-sided tail — a chain of active star formation regions. The final confirmation galaxy status of the jellyfish was possible by conducting a spectral analysis of additional observations made with the «Gemini» observatory.

Astronomers have found that the length of the tail exceeds 20 thousand light-years. Young stars formed in this tail make up about 1% of the galaxy’s mass. Their age does not exceed 100 million years. At the same time star formation continues in the galaxy itself: it is estimated that about 90 solar masses of stars are formed in it per year.

COSMOS2020-635829 has become the first confirmed jellyfish galaxy with an ionized gas tail at such a great distance from Earth. According to Ian Roberts, astronomers do not know how common this type of galaxy is in deep space. 

This one type of galaxy allows astronomers to study in more detail the evolution of galaxies and the process of star formation. Some galaxies in dense environments form far fewer new stars than others, and understanding why is key to understanding how galaxies change over time

The results of the study are published on the preprint server arXiv

Source: LiveScience