RELICS: High-Resolution Constraints on the Inner Mass Distribution of
  the z=0.83 Merging Cluster RXJ0152.7-1357 from strong lensing
  Strong gravitational lensing (SL) is a powerful means to map the distribution
of dark matter. In this work, we perform a SL analysis of the prominent X-ray
cluster RXJ0152.7-1357 (z=0.83, also known as CL 0152.7-1357) in \textit{Hubble
Space Telescope} images, taken in the framework of the Reionization Lensing
Cluster Survey (RELICS). On top of a previously known $z=3.93$ galaxy multiply
imaged by RXJ0152.7-1357, for which we identify an additional multiple image,
guided by a light-traces-mass approach we identify seven new sets of multiply
imaged background sources lensed by this cluster, spanning the redshift range
[1.79-3.93]. A total of 25 multiple images are seen over a small area of ~0.4
$arcmin^2$, allowing us to put relatively high-resolution constraints on the
inner matter distribution. Although modestly massive, the high degree of
substructure together with its very elongated shape make RXJ0152.7-1357 a very
efficient lens for its size. This cluster also comprises the third-largest
sample of z~6-7 candidates in the RELICS survey. Finally, we present a
comparison of our resulting mass distribution and magnification estimates with
those from a Lenstool model. These models are made publicly available through
the MAST archive.
