Spate Galaxien. Die Form der Spiralarmfilamente.

A study is conducted of the shapes of spiral arm filaments in 18 late-type galaxies in order to test the SSPSF theory's hyperbolic spiral arm predictions. After subtracting the disk component from the luminosity distribution by image filtering, the directions along which the intensity variations of the extreme Population I are minimal were determined in circular zones around the centers of the deprojected images; this constitutes an objective determination of pitch angles even for galaxies with very short and filamentary arms. The results obtained severely contradict SSPSF theory, instead implying that the spiral arms are wave phenomena exhibiting logarithmic shapes.