# The co-evolution of strong AGN and central galaxies in different environments

**Authors:** V. M. Sampaio, A. Aragón-Salamanca, M. R. Merrifield, R. R. de Carvalho, S. Zhou, I. Ferreras  
**arXiv:** [2307.10435](https://arxiv.org/abs/2307.10435)  
**Date:** 2023-07-19  
**Summary page:** https://www.summarizepaper.com/en/paper/2307.10435v1/

## Key points

- Study explores impact of active galactic nucleus (AGN) feedback on central galaxies
- Sample size of 80,000 SDSS galaxies analyzed
- AGN dominance as primary ionizing mechanism increases with stellar mass
- AGN fraction varies systematically with star-formation activity of galaxies
- AGN feedback plays crucial role in regulating and suppressing star formation
- Seyfert central galaxies tend to acquire early-type morphology while still hosting residual star formation
- Stellar mass influences morphological transformation: low-mass systems become elliptical, high-mass systems maintain spiral morphology
- Potential link between AGN feedback and morphological changes in high-stellar-mass centrals
- AGN fueled by host halo gas reservoirs, can enhance gas reservoir through interactions with satellite galaxies
- Insights into how AGN feedback influences galaxy evolution, role of stellar mass and environment in shaping demographics and morphology of Seyfert galaxies

## Summary

This study explores the impact of active galactic nucleus (AGN) feedback on the evolution of central galaxies using a sample of 80,000 SDSS galaxies. The authors analyze the demographics of optically-selected AGN known as Seyferts, considering their internal properties and environment. They find that the dominance of AGN as the primary ionizing mechanism increases with stellar mass, surpassing star formation for galaxies with stellar masses greater than or equal to $10^{11}M_\odot$. The fraction of AGN varies systematically with the star-formation activity of galaxies. Within the blue cloud, this fraction increases as star-formation activity declines, reaching a maximum near the green valley at approximately 17 ± 4%. As galaxies transition into the red sequence, the AGN fraction decreases. These findings provide evidence that AGN feedback plays a crucial role in regulating and suppressing star formation. The study also reveals that Seyfert central galaxies tend to acquire an early-type morphology while still hosting residual star formation. This suggests that regardless of their environment, Seyfert galaxies evolve from late- to early-type morphology before their star formation is completely quenched. Stellar mass influences this morphological transformation: low-mass systems typically emerge from the green valley with an elliptical morphology (T-Type $\sim -2.5 \pm 0.7$), while high-mass counterparts maintain a spiral morphology deeper into the red sequence. In high-stellar-mass centrals, there is an increase in Seyferts from early- to late-type galaxies indicating a potential link between AGN feedback and morphological changes. Furthermore, analysis suggests that AGN are fueled by their own host halo gas reservoirs but when located in group centrals they can also enhance their gas reservoir through interactions with satellite galaxies. Overall, this study provides valuable insights into how AGN feedback influences galaxy evolution and highlights the role of stellar mass and environment in shaping the demographics and morphology of Seyfert galaxies. The findings contribute to our understanding of the interplay between AGN activity, star formation and galaxy properties.