Chandra ACIS‐I observed‐frame spectra of CXOHDFN J123646.3+621404 along with the best‐fitting absorbed power‐law model, showing the data taken when the focal plane temperature was −110° C (circles), and the data taken when the focal plane temperature was −120° C (crosses). The best‐fitting power‐law photon index is Γ = ﹩1.57^{+0.26}_{-0.22}﹩, and the intrinsic column density is ﹩( 3.97^{+1.41}_{-0.94}) ﹩ × 10²² cm⁻². Bottom: The ordinate, labeled χ, showing the fit residuals in terms of standard deviation with error bars of size 1.