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We review Foyle et al. (2011) previous results, by applying a Fourierintensity phases method to a nine object sample of galaxies. It was found thattwo of the objects (NGC 628 and NGC 5194), with strong two-arm patterns,present positive evidence for long-lived spirals. Only one of the objects (NGC3627) shows the contrary evidence. As determined by an analysis of resolvedmass maps, the rest of the objects can not be included in the analysis becausethey belong to flocculent and multi-arm type of spiral arms, which are notdescribed by density wave theory.

Reviewing the observational evidence against long-lived spiral arms in galaxies