Numerical simulation of YSO jet collimated by toroidal magnetic fields and radiative cooling effect

Abstract The mechanism of generation and collimation of young stellar object jets remains an unsolved problem and is a research hotspot in contemporary astrophysics. Here, we conducted a two-dimensional cylindrical coordinates simulation experiment using radiative magnetic-hydro-dynamic FLASH code and systematically analyzed the effects of toroidal magnetic fields generated by Biermann battery term and radiative cooling effect on jet evolution. In the simulation, strong toroidal magnetic fields are generated at the boundary of the plasma flow. A comparison of jets generated in different cases indicates that the magnetic fields play a significant role in hydrocarbon (CH) plasma jet collimation, surpassing the impact of radiative cooling effects. Additionally, it is observed that the magnetic fields can alter knots velocities. This platform provides a way to investigate the role of toroidal magnetic fields in jet evolution without external devices and provides a better understanding of the evolution of protostellar jets.