Comparison of mid-IR to microwave SEDs. Left: SED of thermal dust emission for dust models without (black lines) and with (magenta lines) nano-silicate dust for G₀ = 1. In both cases, the dash-dotted lines show the contribution of the smallest nano-grains with a < 1 nm that cause the spinning-dust emission. The nano-silicates are those of case 2, which are the closest in size distribution and electric dipole moment to the THEMIS nano-carbon dust. Right: corresponding spinning-dust emission for media with n_H = 0.1 and 30 H cm^–3 as solid and dashed lines, respectively.