Measurement of Galactic Logarithmic Spiral Arm Pitch Angle Using Two-Dimensional Fast Fourier Transform Decomposition

Davis, Benjamin L.; Berrier, J. C.; Shields, D. W.; Kennefick, J.; Kennefick, D.; Seigar, M. S.; Lacy, C. H. S.; Puerari, I.
Referencia bibliográfica

American Astronomical Society, AAS Meeting #219, #246.01

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1
2012
Número de autores
8
Número de autores del IAC
0
Número de citas
0
Número de citas referidas
0
Descripción
A logarithmic spiral is a prominent feature appearing in a majority of observed galaxies. This feature has long been associated with the traditional Hubble classification scheme, but historical quotes of pitch angle of spiral galaxies have been almost exclusively qualitative. We have developed a methodology, utilizing Two-Dimensional Fast Fourier Transformations of images of spiral galaxies, in order to isolate and measure the pitch angles of their spiral arms. Our technique provides a quantitative way to measure this morphological feature. This will allow the precise comparison of spiral galaxy evolution to other galactic parameters and test spiral arm genesis theories. In this work, we detail our image processing and analysis of spiral galaxy images and discuss the robustness of our analysis techniques. The authors gratefully acknowledge support for this work from NASA Grant NNX08AW03A.