Abstract
Using the Herschel PACS and SPIRE FIR/submm data we investigate variations in the dust spectral index beta in the nearby spiral galaxy M33 at a linear resolution of 160 pc. We use an iteration method in two different approaches, single and two-component modified black body models. In both approaches, beta is higher in the central disk than in the outer disk similar to the dust temperature. There is a positive correlation between beta and H alpha as well as with the molecular gas traced by CO(2-1). A Monte-Carlo simulation shows that the physical parameters are better constrained when using the two-component model.