Simulation of the collision of binary white dwarfs using a cubic grid – stability analysis by variation of diffusion constant and resolution

Binary star mergers are often studied using computer simulations. Sometimes, however, such simulations turn out to be unstable, if necessary countermeasures are not applied.

This paper presents a study of the relationship between the resolution of a simulation and the minimal necessary artificial diffusion to keep it stable. In order to accomplish that, a computer simulator was programmed to simulate the merger of a pair of white dwarfs. 20 experiments with different resolutions and diffusion constants were conducted for the same physical process. By comparing them, some were classified to be stable, other unstable. Using this data, the necessary relationship was found. As a surprising result, if the instabilities did grow, the growth rate seemed to depend only on diffusion constant.

Scientific field





Kristjan Kongas

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