We utilize a suite of multiwavelength data , of 9 nearby spirals , to analyze the shock-induced star formation sequence , that may result from a constant spiral pattern speed .
The sequence involves tracers as the HI , CO , 24 \micron , and FUV , where the spiral arms were analyzed with Fourier techniques in order to obtain their azimuthal phases as a function of radius .
It was found that only two of the objects , NGC 628 and NGC 5194 , present coherent phases resembling the theoretical expectations , as indicated by the phase shifts of CO- 24 \micron .
The evidence is more clear for NGC 5194 , and moderate for NGC 628 .
It was also found that the phase shifts are different for the two spiral arms .
With the exception on NGC 3627 , a two-dimensional Fourier analysis showed that the rest of the objects do not exhibit bi-symmetric spiral structures of stellar mass , i.e. , grand design spirals .
A phase order inversion indicates a corotation radius of \sim 89 \arcsec for NGC 628 , and \sim 202 \arcsec for NGC 5194 .
For these two objects , the CO-H \alpha phase shifts corroborate the CO- 24 \micron azimuthal offsets .
Also for NGC 5194 , the CO- 70 \micron , CO- 140 \micron , and CO- 250 \micron phase shifts indicate a corotation region .