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Arxiv: JWST's PEARLS: 119 multiply imaged galaxies behind MACS0416, lensing properties of caustic crossing galaxies, and the relation between halo mass and number of globular clusters at z=0.4 Published: 12/18/2023 9:00:00 PM Updated: 12/18/2023 9:00:00 PM

Paper abstract: We present a new lens model for the z=0.396 galaxy cluster MACSJ0416.1-2403 based on a previously known set of 77 spectroscopicallyconfirmed, multiply imaged galaxies plus an additional set of 42 candidatemultiply imaged galaxies from past HST and new JWST data. The new galaxies lackspectroscopic redshifts but have geometric and/or photometric redshiftestimates that are presented here. The new model predicts magnifications andtime delays for all multiple images. The full set of constraints totals 343,constituting the largest sample of multiple images lensed by a single clusterto date. Caustic-crossing galaxies lensed by this cluster are especiallyinteresting. Some of these galaxies show transient events, most of which areinterpreted as micro-lensing of stars at cosmological distances. Thesecaustic-crossing arcs are expected to show similar events in future, deeperJWST observations. We provide time delay and magnification models for all thesearcs. The time delays and the magnifications for different arcs are generallyanti-correlated, as expected from N-body simulations. In the major sub-halos of the cluster, the dark-matter mass from our lensmodel correlates well with the observed number of globular clusters. Thisconfirms earlier results, derived at lower redshifts, which suggest thatglobular clusters can be used as powerful mass proxies for the halo masses whenlensing constraints are scarce or not available.