Temperature derived using the TLS model (T_TLS ) using the standard parameters given in Table 4, as a function of temperature derived from a modified black-body fit with a free β parameter (T_fit) in the IRAS 100    μm – Herschel 160, 250, 350, and 500    μm channels (black stars), and in the IRAS 100    μm – Planck 350, 550, and 850    μm channels (gray stars). The triangles show the temperatures derived from a modified black-body fit with β = 2, using the IRAS-Herschel channels (black) and the IRAS-Planck channels (gray). The dashed line corresponds to T_fit = T_TLS . The continuous lines show the best polynomial fits.