Spiral triggering of star formation in normal galaxies

We present results for 13 spiral galaxies from a sample of 31, where we have used the method developed by Gonzalez & Graham 1996, to search for and analyze azimuthal color gradients across spiral arms (see figure 1 in Martinez-Garcia et al. 2009). A total of 23 regions were analyzed in the spiral disks. Ten of the galaxies present regions that match theoretical predictions.