Testing theories in barred spiral galaxies

TL;DR

This study tests the manifold theory in barred spiral galaxies by analyzing the relationship between bar strength and spiral arm pitch angle, finding partial support for the theory's predictions.

Contribution

It provides observational evidence linking bar strength to spiral arm pitch angle, supporting the manifold theory of spiral structure formation.

Findings

Galaxies with sustained logarithmic spiral arms support the predicted trend.

Stronger bars are associated with larger spiral arm pitch angles.

Results partially corroborate the manifold theory predictions.

Abstract

According to one version of the recently proposed "manifold" theory that explains the origin of spirals and rings in relation to chaotic orbits, galaxies with stronger bars should have a higher spiral arms pitch angle when compared to galaxies with weaker bars. A sub-sample of barred-spiral galaxies in the Ohio State University Bright Galaxy Survey, was used to analyze the spiral arms pitch angle. These were compared with bar strengths taken from the literature. It was found that the galaxies in which the spiral arms maintain a logarithmic shape for more than 70$\degr$ seem to corroborate the predicted trend.