Examination of The Shape and Surface Brightness Profile of Galaxies’ Spiral Arms

In our work, surface brightness of spiral arms is examined using the method of cross slices. Images of 19 local large galaxies in infrared from S4G survey are utilized. Radial distribution of spiral arms’ surface brightness is studied; it is shown that profiles are often deviate significantly from exponential which is typical for galactic discs. We have also analyzed spiral arms shapes and introduced functions that describe shapes better than commonly used logarithmic spiral.