Rings and bars: unmasking secular evolution of galaxies

TL;DR

This paper reviews recent observational findings on the role of bars and nuclear rings in the secular evolution of galaxies, highlighting their interconnectedness and impact on galaxy structure.

Contribution

It provides a synthesis of new observational data linking bars and rings to galaxy evolution, and discusses future observational prospects.

Findings

Bars and rings are closely linked to galaxy properties.

Gas flow driven by bars influences central galaxy regions.

Upcoming surveys will enhance understanding of secular evolution.

Abstract

Secular evolution gradually shapes galaxies by internal processes, in contrast to early cosmological evolution which is more rapid. An important driver of secular evolution is the flow of gas from the disk into the central regions, often under the influence of a bar. In this paper, we review several new observational results on bars and nuclear rings in galaxies. They show that these components are intimately linked to each other, and to the properties of their host galaxy. We briefly discuss how upcoming observations, e.g., imaging from the Spitzer Survey of Stellar Structure in Galaxies (S4G), will lead to significant further advances in this area of research.