Galaxy Zoo: Mergers - Dynamical Models of Interacting Galaxies

TL;DR

This study uses extensive simulations and citizen science to reconstruct the dynamical histories of merging galaxies, providing a large dataset that enhances understanding of galaxy interactions and star formation triggers.

Contribution

It presents the largest collection of dynamical models of interacting galaxies, utilizing citizen science and extensive simulations to improve understanding of merger histories.

Findings

Models align with star formation timing from starburst studies.

Tidal star formation is triggered shortly after closest approach.

Provides publicly available simulation data for further research.

Abstract

The dynamical history of most merging galaxies is not well understood. Correlations between galaxy interaction and star formation have been found in previous studies, but require the context of the physical history of merging systems for full insight into the processes that lead to enhanced star formation. We present the results of simulations that reconstruct the orbit trajectories and disturbed morphologies of pairs of interacting galaxies. With the use of a restricted three-body simulation code and the help of Citizen Scientists, we sample 10^5 points in parameter space for each system. We demonstrate a successful recreation of the morphologies of 62 pairs of interacting galaxies through the review of more than 3 million simulations. We examine the level of convergence and uniqueness of the dynamical properties of each system. These simulations represent the largest collection of models of interacting galaxies to date, providing a valuable resource for the investigation of mergers. This paper presents the simulation parameters generated by the project. They are now publicly available in electronic format at http://data.galaxyzoo.org/mergers.html. Though our best-fit model parameters are not an exact match to previously published models, our method for determining uncertainty measurements will aid future comparisons between models. The dynamical clocks from our models agree with previous results of the time since the onset of star formation from star burst models in interacting systems and suggests that tidally induced star formation is triggered very soon after closest approach.