For the first time, astronomers have measured the speed in space of high-speed jets that play a key role in the formation of stars and the distribution of vital elements. Jets of matter ejected from stars believed to be ‘cosmic cannibals’ have been measured to travel faster than a third of the speed of light, thanks to a groundbreaking experiment published in 2014. Nature.

The study sheds new light on these violent processes by successfully exploiting nuclear explosions on the surface of stars. Co-author Jakob van den Einden, a Warwick Prize Fellow in the Department of Physics at the University of Warwick, said: “The explosions occurred in neutron stars, which are incredibly dense and are known for their enormous gravitational pull that forces them to swallow gas from their surroundings – a gravitational pull that only black holes surpass.” .

Detailed mechanism of jet formation

“Material, mostly hydrogen, from a closely orbiting star orbits toward the collapsed star and falls onto its surface as snow. As more and more material rains down, the gravitational field compresses it until a nuclear explosion begins. “This explosion also affects jets that shoot out from the falling material and shoot particles into space at very high speeds.”

The team devised a way to measure the speed and properties of the jets by comparing X-ray and radio signals received by the Australian Telescope Compact Array (owned and operated by Australia’s national science agency CSIRO) and the European Space Agency’s (ESA) Integral. Satellite.

Co-author Thomas Russell, of the INAF National Institute for Astrophysics, Palermo, Italy, said: “This gave us an excellent experiment. We got a very short, short-duration pulse of extra material entering the jet, and we could follow the downward motion of the jet to find out the speed of the jet.”

Problems and observation results

Jakob van den Eynden added: “These explosions happen every few hours but you cannot predict exactly when they will happen. So you’ll have to stare at the telescope observations for a long time and hope to catch a few bursts. “During three days of observation, we saw 10 explosions and the firing of jets.”

Jet planes were traveling at approximately 114,000 kilometers per second; This corresponded to an incredible speed of 35-40% of the speed of light. This was the first time astronomers were able to predict and directly observe how a given amount of gas was directed into a jet and accelerated into space.

Co-author Nathalie Degenaar, from the University of Amsterdam in the Netherlands, continued: “Based on previous data, we thought the explosion would destroy the area from which the jet was launched. But we saw the opposite: a strong entry into the jet, not a disruption.”

Researchers believe that the mass and spin of neutron stars and black holes also affect the jets. This study will demonstrate that this research is possible, laying the foundation for future experiments on neutron stars and their jets. Jets can also be caused by catastrophes such as supernova explosions and gamma-ray bursts. The new results will have wide applications in many space exploration.