Accelerating NBODY6 with a graphics processing unit-enabled Particle-Particle Particle-Tree scheme

We describe a modified version of the NBODY6 code for simulating star clusters which greatly improves computational efficiency while sacrificing little in the way of accuracy. The distant force calculator is replaced by a graphics processing unit-enabled Barnes-Hut code, and integration is done with a standard leap frog scheme. Short-range forces continue to use the CPU-based fourth-order Hermite predictor-corrector scheme of NBODY6. Our code outperforms NBODY6 for systems with more than 3 x 10(5) particles and runs more than a factor 2 faster for systems of 10(6) particles with similar energy conservation. Our code should be useful for simulating realistic dense stellar clusters, such as globular clusters or galactic nuclei.

Automated summary

The modified version of the NBODY6 code improves computational efficiency for simulating star clusters with little sacrifice in accuracy. It outperforms NBODY6 for systems with more than 3 x 10(5) particles and runs more than a factor 2 faster for systems of 10(6) particles with similar energy conservation. This code is useful for simulating realistic dense stellar clusters like globular clusters or galactic nuclei.