Spectral energy distribution of XID2028, shown in the rest frame. Red squares indicate the observed photometry, in the UV-optical-NIR-MIR-FIR regime, extracted from the Laigle et al. (2016) catalogue. The blue stars indicate the ALMA bands 7 and 6 data points and 2 mm and 3 mm upper limits from PdBI and ALMA Band 3. In the rest-frame optical range we also over plot the X-shooter spectrum (from Perna et al. 2015). The blue, magenta, and orange curves correspond to the stellar, AGN, and grey-body components found as a best-fit solution of the overall photometry.