Spectrum of SNR G15.9+0.2 around 6.4 keV. The bremsstrahlung continuum is shown in green, Fe K emission in blue. Black points and line are the pn data and best-fit model, respectively. All other background contributions are shown by the dashed black line. As in Fig. 3, we only show one example for MOS (red). Residuals are displayed in the bottom panels. Models used for the iron emission (from left to right): Gaussian with width fixed to zero, Gaussian with free width, two Gaussians with width fixed to zero. See best-fit parameters in Table 4.