Laboratory X-ray emission experiments can help explain astrophysical jet formation phenomena
DOI: 10.1063/1.5142483
Laboratory X-ray emission experiments can help explain astrophysical jet formation phenomena lead image
Jets are common astrophysical phenomena that occur in low-mass young stellar objects (YSOs) within our own galaxy. However, the process of jet formation and its associated X-ray emission remain unclear. In order to gain a better understanding of the X-ray emission mechanisms of YSOs, Xu et al. performed radial foil z-pinch experiments to study the dynamics of the X-rays emitted from jets.
“Hot X-ray emissions from YSO jets with fitted temperatures around 3 keV are difficult to explain since they can neither be caused by the heating of stellar winds nor by the heating of shock,” said author Qiang Xu.
In a z-pinch experiment, an electrical current in a plasma generates a magnetic field in a surrounding foil, allowing scientists to study X-ray jets within the confines of a laboratory.
As current begins to flow through the foil, the foil begins to ablate and expand into the plasma. The magnetic field then pushes the plasma upward, and a magnetic cavity begins to develop, pinching the plasma along the z-axis and forming a precursor jet. The authors found a large burst of X-rays are emitted from the cavity when the magnetic cavity breaks. They propose a possible mechanism in which a high voltage is produced as the magnetic cavity breaks, accelerating high-energy electrons to produce hard X-rays.
Though the researchers note their proposed mechanism is just one of a number of possibilities, they hope these laboratory findings will ultimately help explain astrophysical processes. Their next steps include determining where the X-rays originate and developing a scaling law between the laboratory and space.
Source: “X-ray emission characteristics in magnetically driven plasma jet experiments on PTS facility,” by Qiang Xu, Shaotong Zhou, Kun-lun Wang, Siqun Zhang, Hongchun Cai, Xiao Ren, Pan Liu, Xian bin Huang, Li Zhao, and Wenkang Zou, Matter and Radiation at Extremes (2019). The article can be accessed at https://doi.org/10.1063/1.5120256 .
