Is every strong lens model unhappy in its own way? Uniform modelling of
  a sample of 13 quadruply+ imaged quasars
  Strong-gravitational lens systems with quadruply-imaged quasars (quads) are
unique probes to address several fundamental problems in cosmology and
astrophysics. Although they are intrinsically very rare, ongoing and planned
wide-field deep-sky surveys are set to discover thousands of such systems in
the next decade. It is thus paramount to devise a general framework to model
strong-lens systems to cope with this large influx without being limited by
expert investigator time. We propose such a general modelling framework
(implemented with the publicly available software Lenstronomy) and apply it to
uniformly model three-band Hubble Space Telescope Wide Field Camera 3 images of
13 quads. This is the largest uniformly modelled sample of quads to date and
paves the way for a variety of studies. To illustrate the scientific content of
the sample, we investigate the alignment between the mass and light
distribution in the deflectors. The position angles of these distributions are
well-aligned, except when there is strong external shear. However, we find no
correlation between the ellipticity of the light and mass distributions. We
also show that the observed flux-ratios between the images depart significantly
from the predictions of simple smooth models. The departures are strongest in
the bluest band, consistent with microlensing being the dominant cause in
addition to millilensing. Future papers will exploit this rich dataset in
combination with ground based spectroscopy and time delays to determine
quantities such as the Hubble constant, the free streaming length of dark
matter, and the normalization of the initial stellar mass function.
