James Webb Space Telescope Feed Post

Arxiv: Precision MARS Mass Reconstruction of Abell 2744: Synergizing the Largest Strong Lensing and Densest Weak Lensing Datasets from JWST Published: 8/28/2023 9:01:10 PM Updated: 11/5/2023 6:56:57 AM

Paper abstract: We present a new high-resolution free-form mass model of Abell 2744,combining both weak-lensing (WL) and strong-lensing (SL) datasets from JWST.The SL dataset comprises 286 multiple images, presenting the most extensive SLconstraint to date for a single cluster. The WL dataset, employing photo-zselection, yields a source density of ~ 350 arcmin^{-2}, marking the densestWL constraint ever. The combined mass reconstruction enables thehighest-resolution mass map of Abell 2744 within the ~ 1.8 Mpc\times1.8 Mpcreconstruction region to date, revealing an isosceles triangular structure withtwo legs of ~ 1 Mpc and a base of ~ 0.6 Mpc. Although our algorithmMAximum-entropy ReconStruction ({\tt MARS}) is entirely blind to the clustergalaxy distribution, the resulting mass reconstruction remarkably well tracesthe brightest cluster galaxies with the five strongest mass peaks coincidingwith the five most luminous cluster galaxies within <~ 2''. We do notdetect any unusual mass peaks that are not traced by the cluster galaxies,unlike the findings in previous studies. Our mass model shows the smallestscatters of SL multiple images in both source (~0".05) and image (~0".1)planes, which are lower than the previous studies by a factor of ~ 4. Although{\tt MARS} represents the mass field with an extremely large number of ~300,000 free parameters, it converges to a solution within a few hours thanksto our utilization of the deep learning technique. We make our mass andmagnification maps publicly available.