Ellipses are fit to the 3-sigma isophote of each galaxy. The following plots show the repeatibility of the fitting parameters for the five scans through Hercules.
Four panels are shown, one for each mag bin (to show only sources with approximatly the same integrated flux). For the brighter sources, K < 13.5, the axis ratio repeats to better than 10% (or 0.1 in the ratio dispersion) for the highly elongated galaxies (b/a < 0.7). For the more circular galaxies (b/a > 0.7) the axis ratio breaks down as expected. For the fainter galaxies, K > 13.5, the axis ratio repeats with a dispersion between 10 and 30%.
Similar to the axis ratio results, the brighter galaxies (K < 13) with axis ratios smaller than 0.7 or so have very good position angle repeatibility, the 1-sigma errorbars are hardly visible for most of the set. For the fainter galaxies, the errobars range from 5 to 20 degrees for the inclined subset (b/a < 0.7). For the more circular galaxies, the p.a. repeatibility breaks down as expected.
