Model componets to play with by thawing and freezing. In the case where the Al Kalpha, Si Kalpha, and/or Cu line contributions are small compared to the rest of the spectral signal then the Gaussian should remain frozen. Al Kalpha and Si Kalpha line components for the MOS1 and MOS2 instruments thaw 1 2 3 4 5 6 55 58 freeze Al Kalpha and Cu line components for the pn instrument thaw 105 106 107 113 116 119 120 121 122 123 124 125 freeze 1 2 3 4 5 6 55 58 SWCX Lines thaw 26 29 freeze 26 29