Galactic Rings Revisited. I. CVRHS Classifications of 3962 Ringed Galaxies from the Galaxy Zoo 2 Database

TL;DR

This study classifies 3962 ringed galaxies from the Galaxy Zoo 2 database using the CVRHS system, providing a comprehensive catalog to enhance understanding of galactic rings and their role in galaxy evolution.

Contribution

It presents the first large-scale CVRHS classification of galaxy rings based on citizen science data, comparing results with previous catalogs and highlighting the catalog's content.

Findings

Zoo volunteers identified similar ring features as in the 1995 CSRG catalog.

The catalog includes mainly inner and outer disc rings and lenses.

Less than 1% of galaxies show cataclysmic or encounter-driven rings.

Abstract

Rings are important and characteristic features of disc-shaped galaxies. This paper is the first in a series which re-visits galactic rings with the goals of further understanding the nature of the features and for examining their role in the secular evolution of galaxy structure. The series begins with a new sample of 3962 galaxies drawn from the Galaxy Zoo 2 citizen science database, selected because zoo volunteers recognized a ring-shaped pattern in the morphology as seen in Sloan Digital Sky Survey colour images. The galaxies are classified within the framework of the Comprehensive de Vaucouleurs revised Hubble-Sandage (CVRHS) system. It is found that zoo volunteers cued on the same kinds of ring-like features that were recognized in the 1995 Catalogue of Southern Ringed Galaxies (CSRG). This paper presents the full catalogue of morphological classifications, comparisons with other sources of classifications, and some histograms designed mainly to highlight the content of the catalogue. The advantages of the sample are its large size and the generally good quality of the images; the main disadvantage is the low physical resolution which limits the detectability of linearly small rings such as nuclear rings. The catalogue includes mainly inner and outer disc rings and lenses. Cataclysmic ("encounter-driven") rings (such as ring and polar ring galaxies) are recognized in less than 1\% of the sample.