H0LiCOW VIII. A weak lensing measurement of the external convergence in
  the field of the lensed quasar HE$\,$0435$-$1223
  We present a weak gravitational lensing measurement of the external
convergence along the line of sight to the quadruply lensed quasar
HE$\,$0435$-$1223. Using deep r-band images from Subaru-Suprime-Cam we observe
galaxies down to a 3$\sigma$ limiting magnitude of $\sim 26$ mags resulting in
a source galaxy density of 14 galaxies / arcmin$^2$ after redshift-based cuts.
Using an inpainting technique and Multi-Scale Entropy filtering algorithm, we
find that the region in close proximity to the lens has an estimated external
convergence of $\kappa=-0.012^{+0.020}_{-0.013}$ and is hence marginally
under-dense. We also rule out the presence of any halo with a mass greater than
$M_{\rm vir}=1.6\times10^{14}h^{-1}M_\odot$ (68$\%$ confidence limit). Our
results, consistent with previous studies of this lens, confirm that the
intervening mass along the line of sight to HE$\,$0435$-$1223 does not affect
significantly the cosmological results inferred from the time delay
measurements of that specific object.
