Surface brightness profile along the isophotal major axis of NGC 5128 in the form of the a^1/4 law, as described in the text. Our star count data are shown as the green, black, and red points from the three different HST cameras, along with the best-fitting a^1/4 profile given in Fig. 16, and they assume e = 0.54 for the outer halo, as described above. The dashed line shows the inner-halo surface brightness profile from Dufour et al. (1979), where μ_V is in mag arcsec⁻². The magnitude scale at the right has been shifted vertically to match the inner surface brightness profile with the outer star counts at (a/R_e) = 1.158.