Analysis of the X-ray emission from the inner 3″. Panel a: 0.5−7 keV Chandra spectrum of the BCG (black crosses), with the absorbed power-law model (first row of Table 5) over-plotted as a black line. Panel b: same as in panel a, with the absorbed thermal model (second row of Table 5) over-plotted as a black line. In both panels, the data are binned to 10 cts bin⁻¹ for plotting purposes. Panel c: comparison between the 0.5−2 keV surface brightness profile of the PSF (green points) and that of the Chandra observation of ZwCl 235 in the inner 50 kpc. The gray dashed line marks the size of the extraction region of the BCG spectrum (3″ ∼ 4.7 kpc; see Sect. 4.6).