The behavior of the pitch angle of spiral arms depending on optical wavelength

TL;DR

This study examines how the pitch angle of spiral arms varies with optical wavelength using integral field spectroscopy, revealing wavelength-dependent behavior in some galaxies and constant pitch angles in others.

Contribution

It provides the first observational evidence of wavelength dependence of spiral arm pitch angles and discusses potential physical mechanisms behind this phenomenon.

Findings

Pitch angle increases with wavelength in some galaxies.

Pitch angle remains constant across wavelengths in others.

Results are confirmed with SDSS data.

Abstract

Based on integral field spectroscopy data from the CALIFA survey, we investigate the possible dependence of spiral arm pitch angle with optical wavelength. For three of the five studied objects, the pitch angle gradually increases at longer wavelengths. This is not the case for two objects where the pitch angle remains constant. This result is confirmed by the analysis of SDSS data. We discuss the possible physical mechanisms to explain this phenomenon, as well as the implications of the results.