A Compact Early-type Galaxy at z = 0.6 Under a Magnifying Lens: Evidence
  For Inside-out Growth
  We use Keck laser guide star adaptive optics imaging and exploit the
magnifying effects of strong gravitational lensing (the effective resolution is
FWHM ~ 200 pc) to investigate the sub-kpc scale of an intermediate-redshift (z
= 0.63) massive early-type galaxy being lensed by a foreground early-type
galaxy; we dub this class of strong gravitational lens systems EELs, e.g.,
early-type/early-type lenses. We find that the background source is massive (M*
= 10^{10.9} M_sun) and compact (r_e = 1.1 kpc), and a two-component fit is
required to model accurately the surface brightness distribution, including an
extended low-surface-brightness component. This extended component may arise
from the evolution of higher-redshift `red nuggets' or may already be in place
at z ~ 2 but is unobservable due to cosmological surface brightness dimming.
