Cross-method analysis of co-rotation radii dataset for spiral galaxies

TL;DR

This study compiles and analyzes a large dataset of co-rotation radius measurements in spiral galaxies, revealing inconsistencies and potential transient spiral structures, and provides a resource for future research.

Contribution

It presents the first comprehensive dataset of co-rotation radii for 547 galaxies and analyzes measurement inconsistencies across different methods.

Findings

Most galaxies show inconsistent co-rotation radius measurements.

Large error coverage and uniform measurement distribution are common.

Results suggest many spirals may be transient rather than steady structures.

Abstract

A co-rotation radius is a key characteristic of disc galaxies that is essential to determine the angular speed of the spiral structure $\Omega_{p}$, and therefore understand its nature. In the literature, there are plenty of methods to estimate this value, but do these measurements have any consistency? In this work, we collected a dataset of corotation radius measurements for 547 galaxies, 300 of which had at least two values. An initial analysis reveals that most objects have rather inconsistent corotation radius positions. Moreover, a significant fraction of galactic discs is distinguished by a large error coverage and almost uniform distribution of measurements. These findings do not have any relation to spiral type, Hubble classification, or presence of a bar. Among other reasons, obtained results could be explained by the transient nature of spirals in a considerable part of galaxies. We have made our collected data sample publicly available, and have demonstrated on one example how it could be useful for future research by investigating a winding time value for a sample of galaxies with possible multiple spiral arm patterns.