Formation of filaments in the collision of a shock wave with two molecular clouds
A mathematician of Moscow State University together with a Russian colleague modeled the formation of filaments (conglomerates of filamentary substances) after a collision of a shock wave with molecular clouds in interstellar space. This work should help to better understand the process of the birth of stars and star systems.
The researchers examined the situation of the shock wave from a supernova explosion reaching clusters of molecular clouds with a high level of density. Large-scale molecular clouds, referred to as "star cradles," are the birthplace of new stars. The shock wave travels at supersonic speeds and changes the cloud structure, creating high and low density areas as well as filamentous structures. In addition, it sets in motion the flow of matter and bends the trajectory, causing turbulence in the outer boundaries of the cloud. This phenomenon is called the Richtmyer-Meshkov instability.
Scientists have proposed a model that describes the formation of a vortex of matter and filaments after the passage of a shock wave. They studied the effect of density distribution along the radius and cloud forms on the contact process between the shock wave and molecular clouds, as well as the occurrence and redistribution of material flows, the formation of filaments and areas of high density. The model consists of 4 billion computing nodes. To reduce the processing time of such a huge amount of information, we had to resort to parallel computing while working with different databases. Modeling has shown that the formation of filaments and uneven distribution of density levels are based on the compression of the cloud substance under the influence of a shock wave.
At the first stage, vortex structures are formed, followed by the propagation of a shock wave and the Richtmyer-Meshkov instability, where matter flows are accelerated. At the very end, the filaments collide in areas of high density and create protostars. Researchers believe that further improving the model will help to understand how stars and star systems form in dense regions of molecular clouds.