The systematics of galaxy morphology in the comprehensive de Vaucouleurs revised Hubble–Sandage classification system: application to the EFIGI sample

This paper is the third which examines galaxy morphology from the point of view of comprehensive de Vaucouleurs revised Hubble–Sandage (CVRHS) classification, a variation on the original de Vaucouleurs classification volume that accounts for finer details of galactic structure, including lenses, nuclear structures, embedded discs, boxy and discy components, and other features. The classification is applied to the ‘Extraction of the idealized forms of galaxies in images’ (EFIGI) sample, a well-defined set of nearby galaxies which were previously examined by Baillard et al. and de Lapparent et al. The survey is focused on statistics of features, and brings attention to exceptional examples of some morphologies, such as skewed bars, blue bar ansae, bar-outer pseudo-ring misalignment, extremely elongated inner SB rings, outer rings and lenses, and other features that are likely relevant to galactic secular evolution and internal dynamics. The possibility of using these classifications as a training set for automated classification algorithms is also discussed.