Morphological classification of galaxies and its relation to physical properties

TL;DR

This paper introduces an integrated approach combining galaxy morphology and physical properties using the QMM method and Pixel-z analysis, revealing correlations between galaxy structure and underlying physical characteristics.

Contribution

It extends the QMM morphological classification to include physical properties, enabling a more comprehensive understanding of galaxy evolution.

Findings

The method successfully relates physical property distributions to morphological features.

Physical properties can be predicted from morphological parameters with significant accuracy.

The approach provides insights into the origin and evolution of galaxy morphology.

Abstract

We extend a recently developed galaxy morphology classification method, Quantitative Multiwavelength Morphology (QMM), to connect galaxy morphologies to their underlying physical properties. The traditional classification of galaxies approaches the problem separately through either morphological classification or, in more recent times, through analysis of physical properties. A combined approach has significant potential in producing a consistent and accurate classification scheme as well as shedding light on the origin and evolution of galaxy morphology. Here we present an analysis of a volume limited sample of 31703 galaxies from the fourth data release of the Sloan Digital Sky Survey. We use an image analysis method called Pixel-z to extract the underlying physical properties of the galaxies, which is then quantified using the concentration, asymmetry and clumpiness (CAS) parameters. The galaxies also have their multiwavelength morphologies quantified using QMM, and these results are then related to the distributed physical properties through a regression analysis. We show that this method can be used to relate the spatial distribution of physical properties with the morphological properties of galaxies.