Top panel: the residual emission-line spectrum after subtracting the best-fit model (i.e., the red curve in the middle panel) from the MIRI/MRS spectrum. From the left to the right, the short lines in the top indicate the positions of [Fe II] 5.34, [Fe VIII] 5.45, [Mg VII] 5.50, [Mg V] 5.61, H2 S(6), H2 S(5), [Ar II] 6.985, [Na III] 7.32, Pfα, [Ne VI] 7.65, [Fe VII] 7.815, [Ar V] 7.90, H2 S(4), [Ar III] 8.99, [Fe VII] 9.53, H2 S(3), [S IV] 10.51, H2 S(2), Huα, [Ne II] 12.81, [Ar V] 13.10, [Ne V] 14.32, [Ne III] 15.555, and H2 S(1) emission lines. Middle panel: illustration of the multicomponent fitting for PAH measurements (see Section 2.2). The gray curve is the observed MIRI/MRS spectrum with emission lines masked. The red curve gives the best-fit model with the shaded region indicating the corresponding 1σ posterior distribution. The blue curve is the summation of all continuum components (i.e., stellar and dust continuum), and these green curves are Drude profiles representing individual PAH features. Bottom panel: the residual PAH spectrum (i.e., the black curve) after subtracting all continuum components (i.e., the blue curve in the middle panel) from the emission-line masked MIRI/MRS spectrum. As in the middle panel, these green curves are Drude profiles representing individual PAH features, and the magenta curve is the summation of all green curves, i.e., the modeled PAH spectrum. From the left to the right, the short lines in the top indicate the positions of PAH complexes around 6.2, 7.7, 8.6, 11.3, and 12.7 μm. Note that all x-axes and the y-axis of the middle panel are in logarithmic scale, while y-axes of the top and bottom panels are in linear scale. The same plots for all apertures studied here are available from Figure A1 in the Appendix.