When clouds collide, destruction and creation go hand in hand

All stars are born from collapsing clouds of dust and gas. But triggering star formation is a difficult process, because these gas clouds do nothing for billions of years. Two researchers have come up with a precise recipe for getting gas clouds to trigger star formation. It involves a lot of collision.

When clouds of gas collide, several things happen at once. Gas and dust entangle each other and instantly create turbulent ripples that race throughout the newly consolidated cluster. Shock waves can also form, which travel at their own speed through the chaos. In every chaos pockets of cloud can destabilize. When they do, they get pinched from the rest of the cloud and collapse rapidly as the force of gravity within them overwhelms any other form of support.

When this happens, clusters of stars form. Astronomers have long suspected this story to be true, but mysteries remain about the details of how a cloud of gas turns into stars. So two researchers investigated this in detail. They have studied how the sizes and velocities of masses of gas lead to different rates of star formation.

They found that the biggest influence on star formation was not the properties of the gas clouds themselves but the background in which they found themselves. For example, if two gas clouds merge together in a relatively high-density environment, the gas clumps tend to produce tighter fusion remnants. This leads to fewer but more massive stars. Conversely, if gas clouds are relatively isolated, they produce more stars but less mass.

This is just one piece of the larger puzzle of trying to understand the history of star formation and under what conditions what kind of stars our galaxy produces.

Research published on arXiv Prepress server.