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arXiv · 2003.13836

Classification and Evolution of Galaxies According to the Dynamical State of Host Clusters and Galaxy Luminosities

D. F. Morell·A. L. B. Ribeiro·R. R. de Carvalho·S. B. Rembold·P. A. A. Lopes·A. P. Costa
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Abstract

We analyze the dependence of galaxy evolution on cluster dynamical state and galaxy luminosities for a sample of 146 galaxy clusters from the Yang SDSS catalog. Clusters were split according to their velocity distribution in Gaussians (G) and Non-Gaussians (NG), and further divided by luminosity regime. We performed a classification in the Age-SSFR plane providing three classes: star-forming (SF), passive (PAS), and intermediate (GV -- green valley). We show that galaxies evolve in the same way in G and NG systems, but also suggest that their formation histories leads to different mixtures of galactic types and infall patterns. Separating the GV into star-forming and passive components, we find more bright galaxies in the passive mode of NG than in G systems. We also find more intermediate faint galaxies in the star-forming component of NG than in G systems. Our results suggest the GV as the stage where the transition from types Sab and Scd to S0 must be taking place, but the conversion between morphological types is independent of the dynamical stage of the clusters. Analyzing the velocity dispersion profiles, we find that objects recently infalling in clusters have a different composition between G and NG systems. While all galaxy types infall onto G systems, Sab and Scd dominate the infall onto NG systems. Finally, we find that faint Scd in the outskirts of NG systems present higher asymmetries relative to the mean asymmetry of field galaxies, suggesting environmental effects acting on these objects.

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D. F. Morell, A. L. B. Ribeiro, R. R. de Carvalho, S. B. Rembold, P. A. A. Lopes, A. P. Costa. 2020-03-30. Classification and Evolution of Galaxies According to the Dynamical State of Host Clusters and Galaxy Luminosities. https://doi.org/10.1093/mnras/staa881

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