Formation of prestellar regions in collisions of molecular clouds simulations on heterogeneous computers

Abstract

The processes occurring in near and far space have a significant impact on the safety of space flights. Processes such as explosions of supernovae and relativistic jets have a particularly great impact. They arise in quasars, black holes, protostars. Often such structures are observed during the formation of new stars. Such jets have a great impact on the safety of space flights. For example, there is currently no radiation shelter on the International Space Station, so astronauts are at serious risk of getting radiation sickness. In addition, the skin of the orbital station modules consists of aluminum, which accumulates secondary radiation. The formation process of new star systems is the result of complex processes that occur in interstellar gas. These processes include nonlinear interactions of turbulence, gravity, collisions of molecular clouds with each other, as well as rotation and several other factors. The evolution of the formation of superdense substance begins from the moment when it gathers in turbulent flows or is formed by supersonic collisions of molecular clouds with each other, or are formed during the intereaction of molecular clouds with supersonic waves, which are formed during the explosions of supernovae, until the moment when these superdense areas reach the prestellar density. Further, depending on several factors, these superdense formations either collapse or disintegrate and return to the interstellar medium. The analysis of observations allows to conclude that a significant part of the molecular clouds is not gravitationally bound. These conclusions are made based on the virial theorem, which expresses the connection between gravitational and kinetic energy. In this paper, a simulation of large molecular clouds collision in a three-dimensional formulation on ultra-high-resolution grids is carried out. Execution of such calculations requires a lot of computer capacity. The paper presents the results of computer modeling of large-scale processes of filament formation and superdense, gravitationally coupled structurally parallel computation clusters with hybrid architecture. Parallel simulation on supercomputers was conducted with author’s software, which uses a modified second-order Godunov method of accuracy of the Total Variation Diminishion type. Calculations were conducted on grids that contain more than one billion cells (1024 × 1024 × 1024). The gravitational potential is calculated on graphic processors. To refine the calculations, the method of adaptive refinement of the AMR grid is used. Simulation results are presented for cases of frontal collision of two molecular clouds, which density is distributed along the radius according to certain laws.