MAESTRO · Magnetically driven Accretion and Ejection phenomena in aSTROphysics: a numerical study

Many astrophysical phenomena involve highly nonlinear processes which take place on vastly different length- and time-scales: therefore, the modeling of complex astrophysical scenarios necessarily require a time-dependent multiscale approach. The objective of this project is to develop and employ High Performance Computing techniques to solve problems of astrophysical relevance. In particular the main aim is to work out fully three-dimensional models of accretion and ejection phenomena taking place in different astrophysical settings by recurring to high-resolution time-dependent magnetohydrodynamic simulations. The numerical experiments will be carried out by exploiting the PLUTO code for computational astrophysics. More specifically, two main problems have been selected: (1) the acceleration and collimation of astrophysical jets from magnetized accretion disks; (2) the interaction between a stellar magnetosphere and a surrounding accretion disk. These studies are essential to understand the fundamental processes which power astrophysical sources as different as Active Galactic Nuclei and Young Stellar Objects. For both three-dimensional problems the large range of spatial and temporal scales involved will require the use of specific computational tools to maintain an adequate spatial resolution in localized regions, reaching dynamically relevant timescales without excessively increasing the computational costs. With this purpose, we plan to improve existent or develop new grid-based tools to be implemented in the PLUTO framework, such as Adaptive Mesh Refinement or Cubed Sphere gridding. The implementation of these features in the PLUTO code represents a further effort to provide to the scientific community an extremely flexible and advanced public code to solve the most diverse problems in Computational Fluid Dynamics, from engineering to astrophysics.