How Different are Normal and Barred Spirals?

TL;DR

This study compares normal and barred spiral galaxies, finding no significant differences in color or luminosity across most types, but noting some systematic faintness in specific subtypes, which suggests possible evolutionary implications.

Contribution

It provides a comparative analysis of the properties of normal and barred spirals, highlighting potential transient nature of bars and distinct evolutionary paths for certain galaxy types.

Findings

No significant color differences between normal and barred spirals.

SBc galaxies are systematically fainter than Sc galaxies.

Lenticular galaxies S0 and SB0 are systematically fainter than other early-type galaxies.

Abstract

No significant color differences are found between normal and barred spirals over the range of Hubble stages a - ab - b - bc. Furthermore, no significant difference is seen between the luminosity distributions of normal and barred galaxies over the same range of Hubble stages. However, SBc galaxies are found to be systematically fainter than Sc galaxies at 99% confidence. The observation that normal and barred spirals with Hubble stages a - ab - b - bc have indistinguishable intrinsic colors hints at the possibility that the bars in such spiral galaxies might be ephemeral structures. Finally, it is pointed out that lenticular galaxies of types S0 and SB0 are systematically fainter than are other early-type galaxies, suggesting that such galaxies are situated on evolutionary tracks that differ systematically from those of galaxies that lie along the E - Sa - Sb -Sc and E - SBa - SBb - SBc sequences.