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 909 weakly lensed galaxies and 39 multiply-imaged sources comprised of 114 multiple images , including a system of multiply-imaged candidates at z = 7.84 \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 of assumptions on the mass distribution used in other methods .
Convergence , shear , and magnification maps are made publicly available through the HFF website http : //www.stsci.edu/hst/campaigns/frontier-fields .
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 .