2014/12/31 by S. Alireza Mortazavi, Jennifer M. Lotz, Joshua E. Barnes +1
Physics and Astronomy · #Algorithm #Astronomy and Astrophysical Research #Astrophysics #Computer science #Convergence (economics) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Parameter space #Physics #Statistical physics #Statistics #Stellar, planetary, and galactic studies #astro-ph.GA
paper · pdf · doi:10.1093/mnras/stv2364
18 pages, 13 figures, 3 Tables, Accepted for publication in MNRAS
arxiv created 2015/10/12 · openalex publication_date 2015/11/26 · arxiv updated 2017/01/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We develop and test an automated technique to model the dynamics of interacting galaxy pairs. We use Identikit as a tool for modelling and matching the morphology and kinematics of the interacting pairs of equal-mass galaxies. In order to reduce the effect of subjective human judgement, we automate the selection of phase space regions used to match simulations to data, and we explore how selection of these regions affects the random uncertainties of parameters in the best-fitting model. In this work, we use an independent set of gadget SPH simulations as input data to determine the systematic bias in the measured encounter parameters based on the known initial conditions of these simulations. We test both cold gas and young stellar components in the gadget simulations to explore the effect of choosing H i versus H α as the line-of-sight velocity tracer. We find that we can group the results into tests with good, fair, and poor convergence based on the distribution of parameters of models close to the best-fitting model. For tests with good and fair convergence, we rule out large fractions of parameter space and recover merger stage, eccentricity, pericentric distance, viewing angle, and initial disc orientations within 3σ of the correct value. All of tests on prograde–prograde systems have either good or fair convergence. The results of tests on edge-on discs are less biased than face-on tests. Retrograde and polar systems do not converge and may require constraints from regions other than the tidal tails and bridges.