Spatial regularity of the young stellar population in spiral arms of late-type galaxies NGC 895, NGC 5474, and NGC 6946

We investigate the spatial regularity in the distribution of the young stellar population along spiral arms of three late-type spiral galaxies: NGC 895, NGC 5474, and NGC 6946. This study is based on an analysis of photometric properties of spiral arms using Galaxy Evolution Explorer ultraviolet, optical UBVRI, H alpha, and 8 mu m IRAC infrared surface photometry data. Using the Fourier analysis approach, we found features of spatial regularity or quasi-regularity in the distribution of the young stellar population or (and) regular chains of star formation regions in all arms of NGC 895, NGC 5474, and NGC 6946 with characteristic scales of spacing from 350 to 500 pc in different arms, and (or) scales that are multiples of them. These characteristic scales are close to those found earlier in NGC 628, NGC 6217, and M100.