Análise da dinâmica de galáxias satélites: simulações de N-corpos e potenciais analíticos

Abstract

This work investigates the orbital trajectories of satellite galaxies under the gravitational influence of a primary galaxy similar to the Milky Way. Using 𝑁-body simulations with the GADGET-2 software and analytical models, the study compares the results to evaluate the impact of the satellite galaxies’ mass on orbital dynamics and the accuracy of analytical models. The main objectives include analyzing the impact of satellite galaxies’ mass on their orbital dynamics and assessing the accuracy of analytical models. The masses of the satellite galaxies ranged from 1 × 109𝑀⊙ to 1 × 107𝑀⊙, exploring how these variations affect orbital dynamics. The methodology involved performing 𝑁-body simulations and applying analytical potentials to model the trajectories. The results indicate that, on shorter time scales or with smaller masses, the analytical models are effective, presenting results similar to those of the 𝑁-body simulations. However, the accuracy of the analytical models decreases with the increase in the satellite galaxies’ mass and their proximity to the core of the central galaxy. The 𝑁-body simulations were conducted for various orbital configurations, with orbits ranging from 70 kpc to 2 kpc. The initial velocities of the satellite galaxies were adjusted to match the circular velocity required for a stable orbit or reduced to 70% of the circular velocity. This procedure allowed for a comprehensive analysis of orbital dynamics in different gravitational scenarios. It is concluded that the analytical models can replace 𝑁-body models in specific situations, providing a less computationally expensive alternative. However, it is essential to consider the limitations of analytical models, especially in conditions involving larger satellite galaxies’ masses and proximity to the galactic core.