Melanie Galloway - UMN
"Galaxy Zoo Hubble: First results of the redshift evolution of disk fraction in the red sequence"
The transition of galaxies from the blue cloud to the red sequence is commonly linked to a morphological transformation from disk to elliptical structure. However, the correlation between color and morphology is not one-to-one, as evidenced by the existence of a significant population of red disks. As this stage in a galaxy's evolution is likely to be transitory, the mechanism by which red disks are formed offers insight to the processes that trigger quenching of star formation and the galaxy's position on the star-forming sequence. I use a large sample of galaxies from the Galaxy Zoo: Hubble project, which uses crowdsourced visual classifications, to study the population of disk galaxies in the red sequence as a function of cosmic time. Preliminary results confirm that the fraction of disks in the red sequence decreases as the Universe evolves from z = 1 to z=0.3.