Observed 3.6 μm magnitude vs. semi-major axis (SMA) for the inner and outer disks of NGC 5523, from the Ellipse analysis displayed in Fig. 1c. In this plot, SMA = 0 is located at the center of the brightness minimum, and thus the plateau beginning at ~1.8 kpc denotes the presence of the nucleated bulge. Outside the inner disk (starting ~6 kpc), the slope of the outer disk photometry is ~0.34 (displayed as ~−0.34 above). The radial scale length of the outer disk is ~1.4 kpc. The error in magnitude for the inner disk is less than 0.1, improving inward (not shown). Error maximizes at 0.3 in the outer disks (~3σ), dominated by systematic background errors. All error measurements are approximate due to uncertainties in the background subtraction.