RELICS: Strong Lensing analysis of the galaxy clusters Abell S295, Abell
  697, MACS J0025.4-1222, and MACS J0159.8-0849
  We present a strong-lensing analysis of four massive galaxy clusters imaged
with the Hubble Space Telescope in the Reionization Lensing Cluster Survey. We
use a Light-Traces-Mass technique to uncover sets of multiply images and
constrain the mass distribution of the clusters. These mass models are the
first published for Abell S295 and MACS J0159.8-0849, and are improvements over
previous models for Abell 697 and MACS J0025.4-1222. Our analysis for MACS
J0025.4-1222 and Abell S295 shows a bimodal mass distribution supporting the
merger scenarios proposed for these clusters. The updated model for MACS
J0025.4-1222 suggests a substantially smaller critical area than previously
estimated. For MACS J0159.8-0849 and Abell 697 we find a single peak and
relatively regular morphology, revealing fairly relaxed clusters. Despite being
less prominent lenses, three of these clusters seem to have lensing strengths,
i.e. cumulative area above certain magnification, similar to the Hubble
Frontier Fields clusters (e.g., A($\mu>5$) $\sim 1-3$ arcmin$^2$, A($\mu>10$)
$\sim 0.5-1.5$ arcmin$^2$), which in part can be attributed to their merging
configurations. We make our lens models publicly available through the Mikulski
Archive for Space Telescopes. Finally, using Gemini-N/GMOS spectroscopic
observations we detect a single emission line from a high-redshift
$J_{125}\simeq25.7$ galaxy candidate lensed by Abell 697. While we cannot rule
out a lower-redshift solution, we interpret the line as Ly$\alpha$ at
$z=5.800\pm 0.001$, in agreement with its photometric redshift and dropout
nature. Within this scenario we measure a Ly$\alpha$ rest-frame equivalent
width of $52\pm22$ \AA, and an observed Gaussian width of $117\pm 15$ km/s.
