Advanced Morphological Galaxy Classification: A Comparison of Real and Simulated Galaxies

TL;DR

This study compares the morphological features of simulated and real galaxies using CAS parameters, revealing similarities in concentration and correlations with color and Hubble type, but also differences in asymmetry and clumpiness.

Contribution

It provides a detailed comparison of simulated and observed galaxy morphologies using advanced statistical measures, highlighting areas of agreement and discrepancy.

Findings

Simulated galaxies have comparable concentration to real galaxies.

Simulated galaxies are more asymmetric than observed.

Clumpiness values in simulations extend beyond observed ranges.

Abstract

Encoded within the morphological structure of galaxies are clues related to their formation and evolutionary history. Recent advances pertaining to the statistics of galaxy morphology include sophisticated measures of concentration (C), asymmetry (A), and clumpiness (S). In this study, these three parameters (CAS) have been applied to a suite of simulated galaxies and compared with observational results inferred from a sample of nearby galaxies. The simulations span a range of late-type systems, with masses between ~1e10 Msun and ~1e12 Msun, and employ star formation density thresholds between 0.1 cm^-3 and 100 cm^-3. We have found that the simulated galaxies possess comparable concentrations to their real counterparts. However, the results of the CAS analysis revealed that the simulated galaxies are generally more asymmetric, and that the range of clumpiness values extends beyond the range of those observed. Strong correlations were obtained between the three CAS parameters and colour (B-V), consistent with observed galaxies. Furthermore, the simulated galaxies possess strong links between their CAS parameters and Hubble type, mostly in-line with their real counterparts.