Optimizing Numerical Simulations of Colliding Galaxies. II. Comparing Simulations to Astronomical Observations

Our research focuses on determining the dynamical orbital parameters associated with galaxy collisions. We are accomplishing this by optimizing numerical models of galactic interactions with astronomical observations of colliding galaxies and measuring the uncertainty in the parameter space of these models. This paper will focus on how we compare our numerical models to observed colliding galaxies. We create gravitational n -body models that capture the tidal distortions from galaxy collisions. The final particle positions are then processed to create model images that have realistic intensity profiles and resolutions. We compare the model’s output with the astronomical images to obtain an objective machine score that should reflect the fitness of the model. To test our scoring methods, we then compare our machine scores to the human-scores obtained from the citizen science project Galaxy Zoo: Mergers.