Predicted free-free emission from a colliding wind binary. We have adopted the parameters v₁ = 10³ km s^-1, ṁ₁ = 1.25 × 10^-5 M_⊙ yr^-1, and v₂ = 10³ km s^-1, ṁ₂ = 5 × 10^-5 M_⊙ yr^-1 for the wind sources. The binary separation is set to D = 4 AU. The dotted and dashed lines represent the fluxes (∝ ν^0.6) from the wind sources 1 and 2 (see also Fig. 1), respectively. The intrinsic thermal emission from the WCR (dot-dashed line) and the total emission (solid line) from the binary system are also shown. The behavior of the curves is described in the main text.