Mass and Light of Abell 370: A Strong and Weak Lensing Analysis
  We present a new gravitational lens model of the Hubble Frontier Fields
cluster Abell 370 ($z = 0.375$) using imaging and spectroscopy from Hubble
Space Telescope and ground-based spectroscopy. We combine constraints from a
catalog of 1344 weakly lensed galaxies and 39 multiply-imaged sources comprised
of 114 multiple images, including a system of multiply-imaged candidates at
$z=7.93 \pm 0.02$, to obtain a best-fit mass distribution using the cluster
lens modeling code Strong and Weak Lensing United. As the only analysis of A370
using strong and weak lensing constraints from Hubble Frontier Fields data, our
method provides an independent check on assumptions in other methods on the
mass distribution. Convergence, shear, and magnification maps are made publicly
available through the HFF website. We find that the model we produce is similar
to models produced by other groups, with some exceptions due to the differences
in lensing code methodology. In an effort to study how our total projected mass
distribution traces light, we measure the stellar mass density distribution
using Spitzer/Infrared Array Camera imaging. Comparing our total mass density
to our stellar mass density in a radius of 0.3 Mpc, we find a mean projected
stellar to total mass ratio of $\langle f* \rangle = 0.011 \pm 0.003$ (stat.)
using the diet Salpeter initial mass function. This value is in general
agreement with independent measurements of $\langle f* \rangle$ in clusters of
similar total mass and redshift.
