Supernovae can create shock waves that may stimulate the formation of new stars, a process that researchers have now recreated using tiny balls of foam and laser beams
12 April 2022
Simulating clouds of gas in space with foam balls and laser beams is helping us figure out how supernovae can stimulate star formation. These small-scale experiments could deepen our understanding of the formation of our own solar system, which may have been born in such a cloud.
Astrophysicists think that molecular clouds, which are billowing clumps of gas, dust and space, can become stellar nurseries when they interact with shock waves from supernovae. In theory, the shock waves stretch and squeeze the gas and create dense areas that can then collapse into stars. This process is difficult to study in detail from afar, though, and it includes complex dynamical effects such as turbulence that are difficult to simulate in computers.
One solution is to build models of these systems in a laboratory that behave similarly and can be observed in detail. Bruno Albertazzi at the École Polytechnique in Paris and his colleagues used a sphere of carbon-hydrogen foam about 1 millimetre across to represent the molecular cloud.
They placed the sphere in a chamber with a small carbon pin, then fired a high-energy laser at the pin, rapidly heating it until it exploded. “It’s similar to the explosion of a star, but much smaller,” says Albertazzi. This explosion sent a shock wave through the foam similar to the shock wave that a supernova could send through a molecular cloud.
The researchers then analysed the foam ball to see if it ended up with any anomalously dense spots after the shock wave passed. These spots would represent the dense areas in a molecular cloud that could then collapse in on themselves to form stars.
They found a small amount of compression, but saw 30 per cent more when they set off two explosions instead of one. This suggests the process might be more important in parts of the universe where there are lots of stars of the same age, and therefore lots of supernovae. However, it will take more detailed observations of these experiments to see the true extent of the compression and how important this process is in the universe, says Albertazzi.
Journal reference: Matter and Radiation at Extremes, DOI: 10.1063/5.0068689
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