Galaxy And Mass Assembly:galaxy morphology in the green valley, prominent rings, and looser spiral arms

Smith, Dominic and Haberzettl, Lutz and Porter, L E and Porter-Temple, Ren and Henry, Christopher P A and Holwerda, Benne and López-Sánchez, Á R and Phillipps, Steven and Graham, Alister W and Brough, Sarah and Pimbblet, Kevin A and Liske, Jochen and Kelvin, Lee S and Robertson, Clayton D and Roemer, Wade and Walmsley, Michael and O’Ryan, David and Géron, Tobias (2022) Galaxy And Mass Assembly:galaxy morphology in the green valley, prominent rings, and looser spiral arms. Monthly Notices of the Royal Astronomical Society, 517 (3). pp. 4575-4589. ISSN 0035-8711

[thumbnail of smith_stac2258]
Text (smith_stac2258)
smith_stac2258.pdf - Published Version

Download (3MB)
[thumbnail of Galaxy_Morphology_in_the_Green_Valley__Dominic_Smith___MNRAS_R2]
Text (Galaxy_Morphology_in_the_Green_Valley__Dominic_Smith___MNRAS_R2)
Galaxy_Morphology_in_the_Green_Valley_Dominic_Smith_MNRAS_R2.pdf - Accepted Version
Available under License Creative Commons Attribution-NonCommercial.

Download (1MB)


Galaxies fall broadly into two categories: star-forming (blue) galaxies and quiescent (red) galaxies. In between, one finds the less populated ‘green valley’. Some of these galaxies are suspected to be in the process of ceasing their star formation through a gradual exhaustion of gas supply, or already dead and experiencing a rejuvenation of star formation through fuel injection. We use the Galaxy And Mass Assembly (GAMA) database and the Galaxy Zoo citizen science morphological estimates to compare the morphology of galaxies in the green valley with those in the red sequence and blue cloud. Our goal is to examine the structural differences within galaxies that fall in the green valley, and what brings them there. Previous results found that disc features such as rings and lenses are more prominently represented in the green-valley population. We revisit this with a similar sized data set of galaxies with morphology labels provided by the Galaxy Zoo for the GAMA fields based on new Kilo-Degree Survey (KiDS) images. Our aim is to compare the results from expert classification qualitatively with those of citizen science. We observe that ring structures are indeed found more commonly in green-valley galaxies compared with their red and blue counterparts. We suggest that ring structures are a consequence of disc galaxies in the green valley actively exhibiting the characteristics of fading discs and evolving disc morphology of galaxies. We note that the progression from blue to red correlates with loosening spiral-arm structure.

Item Type:
Journal Article
Journal or Publication Title:
Monthly Notices of the Royal Astronomical Society
Additional Information:
This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The definitive publisher-authenticated version Dominic Smith, Lutz Haberzettl, L E Porter, Ren Porter-Temple, Christopher P A Henry, Benne Holwerda, Á R López-Sánchez, 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 Géron, Galaxy And Mass Assembly: galaxy morphology in the green valley, prominent rings, and looser spiral arms, Monthly Notices of the Royal Astronomical Society, Volume 517, Issue 3, December 2022, Pages 4575–4589, is available online at:
Uncontrolled Keywords:
ID Code:
Deposited By:
Deposited On:
19 Dec 2022 14:25
Last Modified:
09 Oct 2023 00:48