# Galaxy And Mass Assembly: Galaxy Morphology in the Green Valley, Prominent rings and looser Spiral Arms

**Authors:** Dominic Smith, Lutz Haberzettl, L. E. Porter, Ren Porter-Temple, Christopher P. A. Henry, Benne Holwerda, A. R. Lopez-Sanchez, Steven Phillipps, Alister W. Graham, Sarah Brough, Kevin A. Pimbblet, Jochen Liske, Lee S. Kelvin, Clayton D. Robertson, Wade Roemer, Michael Walmsley, David O'Ryan, Tobias Geron  
**arXiv:** [2211.08355](https://arxiv.org/abs/2211.08355)  
**Date:** 2022-11-15  
**Summary page:** https://www.summarizepaper.com/en/paper/2211.08355v1/

## Key points

- Study focuses on the morphology of galaxies in the "green valley"
- Utilizes Galaxy And Mass Assembly database and citizen science morphological estimates from Galaxy Zoo
- Goal is to understand what brings galaxies into the green valley and examine their unique characteristics
- Previous studies suggest disc features, such as rings and lenses, are more commonly found in green valley galaxies
- Authors analyze dataset of galaxies with morphology labels provided by Galaxy Zoo for GAMA fields based on new KiDS images
- Findings confirm that ring structures are more frequently observed in green valley galaxies compared to red and blue counterparts
- Ring structures are a consequence of disc galaxies in the green valley actively exhibiting fading discs and evolving disc morphology
- Correlation between progression from blue to red colors and loosening spiral arm structure
- Study provides insights into structural differences within green valley galaxies and their transitional nature between active star formation and quiescence
- Highlights value of involving non-experts in large-scale morphological analyses of galaxies

## Summary

This study focuses on the morphology of galaxies in the "green valley," which is a less populated region between star-forming (blue) galaxies and quiescent (red) galaxies. The researchers utilize the Galaxy And Mass Assembly database and citizen science morphological estimates from the Galaxy Zoo to compare the structural differences within green valley galaxies against those in the red sequence and blue cloud. The goal of this research is to understand what brings galaxies into the green valley and examine their unique characteristics. Previous studies have suggested that disc features, such as rings and lenses, are more commonly found in green valley galaxies. To further investigate this, the authors analyze a similar-sized dataset of galaxies with morphology labels provided by the Galaxy Zoo for the GAMA fields based on new KiDS images. They aim to compare these results from expert classification to those obtained through citizen science. The findings confirm that ring structures are indeed more frequently observed in green valley galaxies compared to their red and blue counterparts. The researchers propose that these ring structures are a consequence of disc galaxies in the green valley actively exhibiting fading discs and evolving disc morphology. Additionally, they note that there is a correlation between the progression from blue to red colors and a loosening spiral arm structure. Overall, this study provides further insights into the structural differences within green valley galaxies and sheds light on their transitional nature between active star formation and quiescence. By comparing expert classification with citizen science results, it highlights the value of involving non-experts in large-scale morphological analyses of galaxies.