We present a new high-precision parametric strong lensing model of the galaxy cluster MACS J0416.1−2403, at z = 0.396, which takes advantage of the MUSE Deep Lensed Field (MDLF), with 17.1 h integration in the northeast region of the cluster, and Hubble Frontier Fields data. We spectroscopically identify 182 multiple images from 48 background sources at 0.9 < z < 6.2, and 171 cluster member galaxies. Several multiple images are associated to individual clumps in multiply lensed resolved sources. By defining a new metric, which is sensitive to the gradients of the deflection field, we show that we can accurately reproduce the positions of these star-forming knots despite their vicinity to the model critical lines. The high signal-to-noise ratio of the MDLF spectra enables the measurement of the internal velocity dispersion of 64 cluster galaxies, down to mF160W = 22. This allowed us to independently estimate the contribution of the subhalo mass component of the lens model from the measured Faber-Jackson scaling relation. Our best reference model, which represents a significant step forward compared to our previous analyses, was selected from a comparative study of different mass parametrizations. The root-mean-square displacement between the observed and model-predicted image positions is only 0.40″, which is 33% smaller than in all previous models. The mass model appears to be particularly well constrained in the MDLF region. We characterize the robustness of the magnification map at varying distances from the model critical lines and the total projected mass profile of the cluster.

We present a new strong lensing (SL) model of the Hubble Frontier Fields (HFF) galaxy cluster Abell 2744, at z = 0.3072, by exploiting archival Hubble Space Telescope (HST) multiband imaging and Multi Unit Spectroscopic Explorer (MUSE) follow-up spectroscopy. The lens model considers 90 spectroscopically confirmed multiple images (from 30 background sources), representing the largest secure sample for this cluster field prior to the recently acquired James Webb Space Telescope (JWST) observations. The inclusion of the substructures within several extended sources as model constraints allowed us to accurately characterize the inner total mass distribution of the cluster and the position of the cluster critical lines. We included the lensing contribution of 225 cluster members, 202 of which are spectroscopically confirmed. We complemented this sample with 23 photometric member galaxies that are identified with a convolution neural network methodology with a high degree of purity. 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.

Context. The processes responsible for galaxy evolution in different environments as a function of galaxy mass remain heavily debated. Rich galaxy clusters are ideal laboratories in which to distinguish the role of environmental versus mass quenching because they consist of a full range of galaxies and environments. Aims. Using the CLASH-VLT survey, we assembled an unprecedentedly large sample of 1234 spectroscopically confirmed members in Abell S1063. We found a dynamically complex structure at ⟨zcl⟩ = 0.3457 with a velocity dispersion σv = 1380−32+26 km s−1. We investigated cluster environmental and dynamical effects by analysing the projected phase-space diagram and the orbits as a function of galaxy spectral properties. Methods. We classified cluster galaxies according to the presence and strength of the [OII] emission line, the strength of the Hδ absorption line, and colours. We investigated the relation between the spectral classes of galaxies and their position in the projected phase-space diagram. We separately analysed red and blue galaxy orbits. By correlating the observed positions and velocities with the projected phase-space constructed from simulations, we constrained the accretion redshift of galaxies with different spectral types. Results. Passive galaxies are mainly located in the virialised region, while emission-line galaxies lie beyond r200 and are accreted into the cluster at a later time. Emission-line and post-starburst galaxies show an asymmetric distribution in projected phase-space within r200; emission-line galaxies are prominent at Δv/σ ≲ −1.5 and post-starburst galaxies at Δv/σ ≳ 1.5, suggesting that backsplash galaxies lie at high positive velocities. We find that low-mass passive galaxies are accreted into the cluster before high-mass galaxies. This suggests that we observe as passives only the low-mass galaxies that are accreted early into the cluster as blue galaxies. They had the time to quench their star formation. We also find that red galaxies move on more radial orbits than blue galaxies. This can be explained if infalling galaxies can remain blue by moving on tangential orbits.