0.3–1.2 keV spectrum of the excess emission at the position of the bright arc. The spectrum from a background region from outside the Goat Horn complex was subtracted from the data. The on- and off-source (i.e., background) regions are indicated by the upward and downward orange triangles in Fig. 6, respectively. The black and red lines show the best fits for different assumptions on the metal abundance of the hot plasma (Z = Z_⊙ and Z = 0.1 Z_⊙, respectively).