Document Type
Article
Publication Date
1-1-2020
Department
Physics and Astronomy
Abstract
We use multiwavelength data from the Galaxy And Mass Assembly (GAMA) survey to explore the cause of red optical colours in nearby (0.002 < z < 0.06) spiral galaxies. We show that the colours of red spiral galaxies are a direct consequence of some environment-related mechanism(s) that has removed dust and gas, leading to a lower star formation rate. We conclude that this process acts on long time-scales (several Gyr) due to a lack of morphological transformation associated with the transition in optical colour. The specific star formation rate (sSFR) and dust-to-stellar mass ratio of red spiral galaxies is found to be statistically lower than blue spiral galaxies. On the other hand, red spirals are on average 0.9 dex more massive, and reside in environments 2.6 times denser than their blue counterparts. We find no evidence of excessive nuclear activity, or higher inclination angles to support these as the major causes for the red optical colours seen in ≳47 per cent of all spirals in our sample. Furthermore, for a small subsample of our spiral galaxies that are detected in H I, we find that the SFR of gas-rich red spiral galaxies is lower by ∼1 dex than their blue counterparts.
ThinkIR Citation
Mahajan, Smriti; Gupta, Kriti Kamal; Rana, Rahul; Brown, M. J.I.; Phillipps, S.; Bland-Hawthorn, Joss; Bremer, M. N.; Brough, S.; Holwerda, Benne W.; Hopkins, A. M.; Loveday, J.; Pimbblet, Kevin; and Wang, Lingyu, "Galaxy and Mass Assembly (GAMA): Properties and evolution of red spiral galaxies" (2020). Faculty and Staff Scholarship. 480.
https://ir.library.louisville.edu/faculty/480
DOI
10.1093/mnras/stz2993
ORCID
0000-0002-4884-6756
