XMM-Newton X-ray spectra of 1RXS J180431.1−273932 and associated best fit lines superimposed for the phenomenological model (left) and the physical model (right). See text for details of the two models. Residuals are reported at the bottom of each panel. Red and black data points refer to MOS 1 and MOS 2, respectively. Green data points are those of the pn camera. (This figure is available in color in the electronic form.)