Non-parametric morphologies of galaxies in the EAGLE simulation

Lucas A. Bignone ... [et al.].

Serie: Trabajos publicados del IAR ; no. 1529

Resumen: We study the optical morphology of galaxies in a large-scalehydrodynamic cosmological simulation, the EAGLE simulation. Galaxymorphologies were characterized using non-parametric statistics (Gini,M₂₀, Concentration, and Asymmetry) derived from mock imagescomputed using a 3D radiative transfer technique and post-processed toapproximate observational surveys. The resulting morphologies werecontrasted to observational results from a sample of log_{10}(M_{*}/{M}_☉) > 10 galaxies at z ∼ 0.05 in the GAMA survey. Wefind that the morphologies of EAGLE galaxies reproduce observations,except for asymmetry values which are larger in the simulated galaxies.Additionally, we study the effect of spatial resolution in thecomputation of non-parametric morphologies, finding that Gini andAsymmetry values are systematically reduced with decreasing spatialresolution. Gini values for lower mass galaxies are especially affected.Comparing against other large-scale simulations, the non-parametricstatistics of EAGLE galaxies largely agree with those found inILLUSTRISTNG. Additionally, EAGLE galaxies mostly reproduce observedtrends between morphology and star formation rate and galaxy size.Finally, We also find a significant correlation between optical andkinematic estimators of morphologies, although galaxy classificationbased on an optical or a kinematic criteria results in different galaxysubsets. The correlation between optical and kinematic morphologies isstronger in central galaxies than in satellites, indicating differencesin morphological evolution