RELICS: A Very Large ($\theta_{E}\sim40"$) Cluster Lens -- RXC
  J0032.1+1808
  Extensive surveys with the \textit{Hubble Space Telescope} (HST) over the
past decade, targeting some of the most massive clusters in the sky, have
uncovered dozens of galaxy-cluster strong lenses. The massive cluster
strong-lens scale is typically $\theta_{E}\sim10\arcsec$ to $\sim30-35\arcsec$,
with only a handful of clusters known with Einstein radii
$\theta_{E}\sim40\arcsec$ or above (for $z_{source}=2$, nominally). Here we
report another very large cluster lens, RXC J0032.1+1808 ($z=0.3956$), the
second richest cluster in the redMapper cluster catalog and the 85th most
massive cluster in the Planck Sunyaev-Zel'dovich catalog. With our
Light-Traces-Mass and fully parametric (dPIEeNFW) approaches, we construct
strong lensing models based on 18 multiple images of 5 background galaxies
newly identified in the \textit{Hubble} data mainly from the
\textit{Reionization Lensing Cluster Survey} (RELICS), in addition to a known
sextuply imaged system in this cluster. Furthermore, we compare these models to
Lenstool and GLAFIC models that were produced independently as part of the
RELICS program. All models reveal a large effective Einstein radius of
$\theta_{E}\simeq40\arcsec$ ($z_{source}=2$), owing to the obvious
concentration of substructures near the cluster center. Although RXC
J0032.1+1808 has a very large critical area and high lensing strength, only
three magnified high-redshift candidates are found within the field targeted by
RELICS. Nevertheless, we expect many more high-redshift candidates will be seen
in wider and deeper observations with \textit{Hubble} or \emph{JWST}. Finally,
the comparison between several algorithms demonstrates that the total error
budget is largely dominated by systematic uncertainties.
