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| Main Authors: | , , , , |
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| Format: | Preprint |
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2025
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| Online Access: | https://arxiv.org/abs/2506.12205 |
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| _version_ | 1866912444830449664 |
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| author | Sampaio, Vitor M. Kolesnikov, Igor de Carvalho, Reinaldo R. Ferreras, Ignacio Silk, Joseph |
| author_facet | Sampaio, Vitor M. Kolesnikov, Igor de Carvalho, Reinaldo R. Ferreras, Ignacio Silk, Joseph |
| contents | We investigate the redshift evolution of disk and bulge-dominated galaxies using a mass-complete sample of $\sim$14,000 galaxies from the CANDELS survey, selected with $H_{\rm mag} \leq 24$, $M_{\rm stellar} \geq 10^9\,{\rm M}_\odot$, and spanning $0.2 \leq z \leq 2.4$. Adopting an unbiased morphological classification, free from visual inspection or parametric assumptions, we explore the evolution of specific star formation rate (sSFR), stellar mass, structural properties, and galaxy fractions as a function of redshift and morphology. We find that while disk and bulge-dominated galaxies exhibit similar sSFR distributions at $z \sim 2.4$, bulge-dominated systems develop a redshift-dependent bimodality below $z < 1.6$, unlike the unimodal behaviour of disks. This bimodality correlates with stellar mass: bulge-dominated galaxies with lower sSFR are significantly more massive and exhibit higher Sérsic indices than their star-forming counterparts, despite having similar effective radii. Based on a Gaussian mixture decomposition, we identify two evolutionary tracks for bulge-dominated galaxies: G1, a long-lived, star-forming population with disk-like properties; and G2, a quenched, massive population whose prominence increases with decreasing redshift. The evolution of the star formation main sequence and morphology--mass fractions support a scenario in which G2 systems form through merger-driven transformations of massive disks. Our results indicate that bulge-dominated galaxies are not a homogeneous population, but instead follow divergent evolutionary paths driven by distinct physical mechanisms. |
| format | Preprint |
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arxiv_https___arxiv_org_abs_2506_12205 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Morphology across cosmic time: assessing the evolution and interplay of disk and bulge-dominated galaxies in the CANDELS survey Sampaio, Vitor M. Kolesnikov, Igor de Carvalho, Reinaldo R. Ferreras, Ignacio Silk, Joseph Astrophysics of Galaxies We investigate the redshift evolution of disk and bulge-dominated galaxies using a mass-complete sample of $\sim$14,000 galaxies from the CANDELS survey, selected with $H_{\rm mag} \leq 24$, $M_{\rm stellar} \geq 10^9\,{\rm M}_\odot$, and spanning $0.2 \leq z \leq 2.4$. Adopting an unbiased morphological classification, free from visual inspection or parametric assumptions, we explore the evolution of specific star formation rate (sSFR), stellar mass, structural properties, and galaxy fractions as a function of redshift and morphology. We find that while disk and bulge-dominated galaxies exhibit similar sSFR distributions at $z \sim 2.4$, bulge-dominated systems develop a redshift-dependent bimodality below $z < 1.6$, unlike the unimodal behaviour of disks. This bimodality correlates with stellar mass: bulge-dominated galaxies with lower sSFR are significantly more massive and exhibit higher Sérsic indices than their star-forming counterparts, despite having similar effective radii. Based on a Gaussian mixture decomposition, we identify two evolutionary tracks for bulge-dominated galaxies: G1, a long-lived, star-forming population with disk-like properties; and G2, a quenched, massive population whose prominence increases with decreasing redshift. The evolution of the star formation main sequence and morphology--mass fractions support a scenario in which G2 systems form through merger-driven transformations of massive disks. Our results indicate that bulge-dominated galaxies are not a homogeneous population, but instead follow divergent evolutionary paths driven by distinct physical mechanisms. |
| title | Morphology across cosmic time: assessing the evolution and interplay of disk and bulge-dominated galaxies in the CANDELS survey |
| topic | Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2506.12205 |