The derived 70-850-m spectral energy distributions of the components contributing to the observed emission from Cas A. See Sect. 3 for a description of how the flux densities from each component at each wavelength were estimated. Red: nonthermal flux densities estimated from a power-law fit between the 6-cm and 3.6-m flux densities; Green: warm dust component flux densities; Blue: flux densities for the cold interstellar dust component. Also shown are a emissivity 17-K fit to the cold IS dust flux densities (blue dashed line), and a comparison with the Dwek et al. (1997) COBE DIRBE/FIRAS average ISM spectral energy distribution (turquoise; shown with the quoted 20% 1 uncertainty limits). Magenta: the derived flux densities for the cool dust component, together with a 35-K emissivity fit (dashed magenta line). The blue points show the PACS and SPIRE 70-500-m total flux densities measured for Cas A, as well as the SCUBA 850-m flux density measured by Dunne et al. (2003). The black dashed line corresponds to the sum of the fits to the nonthermal, warm dust, cool dust and cold IS dust components.