Towards an Understanding of the Massive Red Spiral Galaxy Formation

TL;DR

This study investigates the formation and quenching of massive red spiral galaxies, revealing their bulge-dominated structures, rapid formation history, and potential formation via interactions or mergers, contrasting them with blue spirals.

Contribution

It provides a detailed comparison of red and blue spirals' structural and spectral properties, highlighting the role of bulge formation, mergers, and possible rejuvenation processes.

Findings

Red spirals have compact, bulge-dominated cores with high stellar mass surface densities.

Approximately 70% of red spirals show signs of interactions or mergers.

High $ m \Sigma_1$ blue spirals share properties with red spirals, suggesting possible rejuvenation.

Abstract

To understand the formation and quenching processes of local massive red spiral galaxies with $M_{\ast} > 10^{10.5}M_{\odot}$, we perform a statistical analysis of their spectroscopic and structural properties, and compare them with elliptical and blue spiral galaxies of similar mass. The sample was selected from the stellar mass catalog of galaxies in SDSS DR7, according to their locations on the u-r color-stellar mass diagram. We find that red spirals harbor compact cores with high stellar mass surface densities measured by $\Sigma_1$ and they are bulge-dominated. Particularly, the red spirals, especially their bulges follow the $\Sigma_1$-$M_{\ast}$ ridgeline for quenched galaxies. Furthermore, the red spirals show similarly large central D$_n(4000)$, high [Mg/Fe] and dark matter halo mass to ellipticals. These results suggest that the bulges of red spirals formed within a short timescale before redshift ~ 1-2 and were quenched via a fast mode, similar to ellipticals. Careful examinations of the optical morphologies reveal that ~70% of red spirals show strong bars, rings/shells and even merging features, which suggests that interactions or mergers might have played an important role in the formation of red spirals. In contrast, most of the massive blue spirals have completely different spectral and structural properties from red spirals. However, the blue spirals with high $\Sigma_1$ ($\Sigma_1 > 10^{9.5} M_\odot \, {\rm kpc}^{-2}$) show similar structural and morphological properties, as well as similar halo mass and HI mass to red spirals. We discuss rejuvenation from red to blue as a possible explanation for these high $\Sigma_1$ blue spirals.