Astrophysical jets of magnetized plasma, emanating from supermassive black holes and rapidly rotating neutron stars, are among the most spectacular phenomena in the universe. From their bright radiation emission, which spans the entire electromagnetic spectrum, we infer that these are among the most powerful particles accelerators in the cosmos. Despite decades of observations and theoretical studies, the mechanisms behind these cosmic accelerators remain a long-standing mystery, which continues to fascinate physicists. Beyond its relevance to the understanding of the extreme universe, the study of particle acceleration in plasmas has a significant impact on inspiring the design of new laboratory accelerators for a variety of applications, from fusion to high energy physics research and medical imaging.
An important breakthrough in unveiling how jets may efficiently accelerate high-energy non-thermal particles through current-driven instabilities was achieved via unprecedented 3D ab initio massively particle-in-cell (PIC) simulations. This has opened the way for the exploration of this new acceleration mechanism. However, significantly more work is necessary in order to fully understand the range of parameters where this mechanism can operate, and how it may manifest in different astrophysical classes/regions that possess more complex magnetic field structures and plasma compositions.
Studying the dynamics of jets in subrelativistic regimes, including collisional effects, to determine the necessary conditions to observe the particle acceleration mechanisms associated with astrophysical jets in the laboratory will allow us to guide the design of future experiments aiming at probing the plasma processes and the acceleration mechanisms associated with the extreme cosmic accelerators.