Subaru Telescope adaptive optics observations of gravitationally lensed
  quasars in the Sloan Digital Sky Survey
  We present the results of an imaging observation campaign conducted with the
Subaru Telescope adaptive optics system (IRCS+AO188) on 28 gravitationally
lensed quasars (23 doubles, 1 quad, and 1 possible triple, and 3 candidates)
from the SDSS Quasar Lens Search. We develop a novel modelling technique that
fits analytical and hybrid point spread functions (PSFs), while simultaneously
measuring the relative astrometry, photometry, as well as the lens galaxy
morphology. We account for systematics by simulating the observed systems using
separately observed PSF stars. The measured relative astrometry is comparable
with that typically achieved with the Hubble Space Telescope, even after
marginalizing over the PSF uncertainty. We model for the first time the quasar
host galaxies in 5 systems, without a-priory knowledge of the PSF, and show
that their luminosities follow the known correlation with the mass of the
supermassive black hole. For each system, we obtain mass models far more
accurate than those previously published from low-resolution data, and we show
that in our sample of lensing galaxies the observed light profile is more
elliptical than the mass, for ellipticity > 0.25. We also identify eight
doubles for which the sources of external and internal shear are more reliably
separated, and should therefore be prioritized in monitoring campaigns aimed at
measuring time-delays in order to infer the Hubble constant.
