Examining the properties of spiral galaxies as a function of arm multiplicity with Galaxy Zoo 2
Ross Hart
The University of Nottingham
The Galaxy Zoo Team
Spiral arms are the primary sites of star formation in galaxy disks, yet there has been little study of how their varied appearance relates to a galaxy's mass, star-formation history and environment. An opportunity to analyse the morphologies of nearby galaxies is provided from the visual classifications of over 240,000 galaxies from the Sloan Digital Sky Survey (SDSS) in the Galaxy Zoo 2 citizen science project. A debiasing procedure is applied to the distributions of vote fractions to remove the effect that redshift has on the classifications. The lower image quality of higher redshift SDSS images compared to brighter low redshift images means that some of the more detailed spiral structure can be lost when using the raw vote fractions alone. We separate the Galaxy Zoo 2 spiral galaxies in to separate sub-samples of galaxies with different numbers of spiral arms. This gives us a unique opportunity to study the differences in the stellar populations of galaxies as a function of arm multiplicity, by looking at how properties such as colour and magnitude vary between the different galaxy sub-samples.