Using the Hubble Space Telescope, researchers have observed a gas clump in the early stages of its gravitational collapse for the first time. The activity occurred in a galaxy only three billion years after the Big Bang.

It’s long been predicted that these clumps could form in gas-rich galaxies from larger disks of gas. And once formed, scientists believed the clump would continue to collapse, creating stars in the process. But until now, we've not observed the genesis of a star-forming clump, and there have been some questions about whether these objects would be able to sustain their collapse against the outward pressure created by the forming stars. These stars produce intense light which can actually put a significant amount of pressure on the surrounding gas, accelerating it away. By pushing against the surrounding gas, the first stars can prevent the formation of later ones.

The new observation shows an extremely young clump, less than ten million years old—the researchers project its total lifespan will be about 500 million years. If that’s the case, it and similar clumps could grow into globular clusters, smaller blobs of stars orbiting at angles that bring them drastically away from the plane of the galaxy’s disk. Alternatively, these clumps could even contribute to a galaxy’s central bulge.

As researchers are still piecing together the complicated mechanisms by which galaxies are formed, this is an important discovery. It favors models in which the clumps have long lifetimes. By the authors’ estimate, these bodies at a rate of about 2.5 clumps per galaxy per billion years. The researchers were also able to estimate the rate at which the clump is forming stars: about 10 to 20 times the Sun’s mass (Solar masses) of stars per year.

The researchers used the information to paint a tentative picture (in the form of a high resolution simulation) of the evolution of these star-forming clumps. The clumps, though they only form rarely, initially experience a relatively brief period of rapid star formation. After this burst, feedback from the stars slows the formation of new stars. It doesn’t stop it entirely, however, and the clumps go on to have long lifespans.

“This is crucial to an understanding of key issues of galaxy formation and evolution such as clump migration, bulge formation, and the role of feedback,” the authors write in their paper.

The researchers point out that more studies need to be done to gain a full insight into the bigger picture. Luckily, the new observations show that it’s possible to detect these bodies, and they estimate that the complete Atacama Large Millimeter Array (ALMA) and the forthcoming James Webb Space Telescope should be able to generate a larger survey of these clumps.

Nature, 2015. DOI: 10.1038/nature14409 (About DOIs)