A refined mass distribution of the cluster MACS J0416.1$-$2403 from a
  new large set of spectroscopic multiply lensed sources
  We report the spectroscopic confirmation of 22 new multiply lensed sources
behind the Hubble Frontier Field (HFF) galaxy cluster MACS~J0416.1$-$2403 (MACS
0416), using archival data from the Multi Unit Spectroscopic Explorer (MUSE) on
the VLT. Combining with previous spectroscopic measurements of 15 other
multiply imaged sources, we obtain a sample of 102 secure multiple images with
measured redshifts, the largest to date in a single strong lensing system. The
newly confirmed sources are largely low-luminosity Lyman-$\alpha$ emitters with
redshift in the range [3.08-6.15]. With such a large number of secure
constraints, and a significantly improved sample of galaxy members in the
cluster core, we have improved our previous strong lensing model and obtained a
robust determination of the projected total mass distribution of MACS 0416. We
find evidence of three cored dark-matter halos, adding to the known complexity
of this merging system. The total mass density profile, as well as the sub-halo
population, are found in good agreement with previous works. We update and make
public the redshift catalog of MACS 0416 from our previous spectroscopic
campaign with the new MUSE redshifts. We also release lensing maps
(convergence, shear, magnification) in the standard HFF format.
