Thermal Radio Emission from Radiative Shocks in Colliding Stellar Winds

We present a semi-analytic model for computing the thermal radio continuum emission from radiative shocks within colliding wind binaries. Assuming a thin shell approximation, we determine the contribution of the wind collision region (WCR) to the total thermal emission for close binaries. We investigate the effect of the binary separation and the stellar wind parameters on the total spectrum. In addition, we point out the relevance of taking into account this contribution for the correct interpretation of the observations, and the accuracy of the stellar wind parameters derived from them.