On the limits of measuring the bulge and disk properties of local and
  high-redshift massive galaxies
  A considerable fraction of the massive quiescent galaxies at \emph{z}
$\approx$ 2, which are known to be much more compact than galaxies of
comparable mass today, appear to have a disk. How well can we measure the bulge
and disk properties of these systems? We simulate two-component model galaxies
in order to systematically quantify the effects of non-homology in structures
and the methods employed. We employ empirical scaling relations to produce
realistic-looking local galaxies with a uniform and wide range of
bulge-to-total ratios ($B/T$), and then rescale them to mimic the
signal-to-noise ratios and sizes of observed galaxies at \emph{z} $\approx$ 2.
This provides the most complete set of simulations to date for which we can
examine the robustness of two-component decomposition of compact disk galaxies
at different $B/T$. We confirm that the size of these massive, compact galaxies
can be measured robustly using a single S\'{e}rsic fit. We can measure $B/T$
accurately without imposing any constraints on the light profile shape of the
bulge, but, due to the small angular sizes of bulges at high redshift, their
detailed properties can only be recovered for galaxies with $B/T$ \gax\ 0.2.
The disk component, by contrast, can be measured with little difficulty.
