Hubble captures cosmic ‘pearl necklace’: How was it formed?

NASA's Hubble Space Telescope has unveiled an image of the galaxy AM 1054-325, dubbed the "pearl necklace" for its distinctive appearance – an S-shaped sequence of millions of bright blue stars. This galaxy is one of the 12 observed galactic mergers captured by the Hubble. In the process of their mutual interaction in space, immense tidal tails of material are formed, where millions of stars are simultaneously born. 

Galactic mergers, studied by the Hubble, may have occurred much more frequently in the past. Thus, we can observe processes near us that have long occurred in the rest of the Universe. The mergers of the observed galactic pairs vividly demonstrate that star formation ignites almost simultaneously along the entire length of the tidal tail – a twisted stream of molecular hydrogen formed by the gravitational forces of both galaxies.

If the collision had not occurred, both galaxies would have continued their journey without the intensive birth of new stars and planets. The merger compressed interstellar gas and dust to a state where nuclear reactions began, giving rise to new stars. In the 12 pairs of merging galaxies observed by the Hubble, 425 clusters were identified, each containing approximately one million newborn stars, indicating the intense processes of star formation.

The fate of the newborn stars in the tidal tails remains unknown. Young stars may gather into clusters and accompany their galaxies further on their journey through the Universe, or they may disperse into the galactic halo, or even leave and become intergalactic wanderers. In the end, it is worth acknowledging that a "cosmic collision" in the case of galactic collisions leads not to the demise of the participants but, on the contrary, to the intense birth of numerous new inhabitants of the Universe.