Precision modeling of JWST's first cluster lens SMACSJ0723.3-7327

Understand

Exploiting the fundamentally achromatic nature of gravitational lensing, we present a lens model for the massive galaxy cluster SMACSJ0723.3-7323 (SMACSJ0723, z=0.388) that significantly improves upon earlier work.

• Building on strong-lensing constraints identified in prior Hubble Space Telescope (HST) observations, the mass model utilizes 21 multiple-image systems, 17 of which were newly discovered in Early Release Observation (ERO) data from the James Webb Space Telescope (JWST).
• The resulting lens model maps the cluster mass distribution to an RMS spatial precision of 0.32'' and is publicly available.
• Consistent with previous analyses, our study shows SMACSJ0723.3-7323 to be well described by a single large-scale component centered on the location of the brightest cluster galaxy.