Only spotted by astronomers since 1918, astrophysical jets are narrow streams of matter that emerge with high thrust and power from astrophysical objects. These (enormous) jets exist in newly born stars or galaxies and propagate over enormous distances. Initially seen only as spectacular displays of ejected gas or dust, these ubiquitous objects are now believed to play a crucial role in star formation and evolution. Indeed, without the removal of angular momentum from accreting or collapsing systems by the jets, a collapsed object giving birth to a star would not form. Jets also perturb their environment, triggering star formation in regions close to their paths. But jets have also proved to be extremely useful beacons allowing us to detect distant objects in the universe, like protostars embedded in giant molecular clouds that otherwise could not be discovered. Despite this, they still remain amongst the most mysterious phenomena of modern astronomy.
Using a combination of powerful lasers and ultra-strong magnetic fields, researchers from the CNRS the UPMC and the Observatoire de Paris were able to produce in the laboratory scaled astrophysical jets. By combining the laboratory jets to supercomputer simulations, they showed that an essential ingredient to generate narrow jets that are scalable to observations in the presence of large-scale magnetic field. These results, published in the Science magazine, shed light on how astrophysical winds ejected from proto-stars and their accretion disks can be collimated into jets, and on the puzzling observations obtained with the CHANDRA satellite, of bright x-ray emission along the jet flow.
This work is the culmination of an interdisciplinary collaboration between the laboratories LULI in Palaiseau, the LNCMI in Toulouse, the LERMA in Paris, and international collaborators, which has also seen the development of a unique experimental device that was recently patented.