# A Comprehensive Examination of the Optical Morphologies of 719 Isolated Galaxies in the AMIGA Sample

## TL;DR

This study re-examines the optical morphologies of 719 isolated galaxies from the AMIGA sample using SDSS data, classifying them with the CVRHS system and analyzing features like bars, rings, and spiral arms to understand their properties and environmental relations.

## Contribution

It provides a detailed morphological classification of isolated galaxies using the CVRHS system and investigates the prevalence of features like bars and spiral arm classes in this unique sample.

## Key findings

- Isolated galaxies span the full Hubble sequence, with a higher occurrence of intermediate to late-type spirals.
- Over 50% of spirals are grand design, indicating prominent spiral structures.
- Approximately 50% of the sample have bars, but only 16% are strongly barred.

## Abstract

Using images from Sloan Digital Sky Survey Data Release 8, we have re-examined the morphology of 719 galaxies from the Analysis of the interstellar Medium in Isolated GAlaxies (AMIGA) project, a sample consisting of the most isolated galaxies that have yet been identified. The goal is to further improve the classifications of these galaxies by examining them in the context of the Comprehensive de Vaucouleurs revised Hubble-Sandage (CVRHS) system, which includes recognition of features that go beyond the original de Vaucouleurs point of view. Our results confirm previous findings that isolated galaxies are found across the complete revised Hubble sequence, with intermediate to late-type (Sb-Sc) spirals being relatively more common. Elmegreen Arm Classifications are also presented, and show that more than 50% of the 514 spirals in the sample for which an arm class could be judged are grand design (AC 8,9,12). The visual bar fraction for the sample is ~50%, but only 16% are classified as strongly-barred (SB). The dominant family classification is SA (nonbarred), the dominant inner variety classification is (s) (pure spiral), and the dominant outer variety classification is no outer ring, pseudoring, or lens. The Kolmogorov-Smirnov test is used to check for potential biases in the morphological interpretations, and for any possible relation between rings, bars, and arm classes with local environment and far-infrared excess. The connection between morphology and stellar mass is also examined for a subset of the sample.