EPIC-pn spectral residuals of PG 1126-041 to the phenomenological model [(partcov*xstar500)*(xstar5000*pow + zgauss1 + zgauss2)] (left column) and to the disk wind model [(partcov*xstar500)*(fast32*pow)] (right column). The top panel reports the residuals of all eight epochs together, while the smaller individual panels correspond to different epochs of observation, as listed in Table 1.