X-ray and optical SED of sGRB 130603B at the epoch of first millimetre observations i.e. 0.22d after the burst. We plot the best-fitting absorption and extinction corrected spectral model (solid red lines, broken power-law model), as well as the host galaxy absorbed and extinguished spectral model (orange dash lines) and the data (black circles) using the method described in Schady et al. (2010).