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对大质量红旋涡星系形成的理解
2020-09-17 09:09  

20207月该论文发表于ApJ 2020, The Astrophysical Journal, 897, 162  

      To understand the formation and quenching processes of local massive red spiral galaxies with M* > 1010.5 M, 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 Σ1 and are bulge dominated. Particularly, the red spirals, especially their bulges, follow the Σ1-M* ridgeline for quenched galaxies. Furthermore, the red spirals show similarly large central Dn(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 Σ1 ( Σ1>109.5Mkpc2 ) show similar structural and morphological properties, as well as similar halo mass and H I mass to red spirals. We discuss rejuvenation from red to blue as a possible explanation for these high-Σ1 blue spirals.



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