Abell 2744 members

We also measured the internal velocity dispersion of 85 cluster galaxies, down to m_F160W_=22, to independently estimate the role of the subhalo mass component in the lens model. We investigated the effect of the cluster environment on the total mass reconstruction of the cluster core with two different mass parameterizations. We considered the mass contribution from three external clumps, either based on previous weak lensing studies, or extended HST imaging of luminous members around the cluster core.

In the latter case, the observed positions of the multiple images were better reproduced, with a remarkable accuracy of 0.37", a factor of ~2 smaller than previous lens models, which exploited the same HST and MUSE data sets. As part of this work, we developed and made publicly available a Strong Lensing Online Tool (SLOT) to exploit the predictive power and the full statistical information of this and future models, through a simple graphical interface.

We plan to apply our new high-precision SL model to the first analysis of the Grism Lens-Amplified Survey from Space-JWST-Early Release Science (GLASS-JWST-ERS) program, specifically to measure the intrinsic physical properties of high-z galaxies from robust magnification maps.