James Webb Space Telescope Feed Post

Precision MARS Mass Reconstruction of Abell 2744: Synergizing the Largest Strong Lensing and Densest Weak Lensing Datasets from JWST

Mass contours of A2744 overlaid on the color-composite images. The yellow contours indicate the convergence ?. The upper left (upper right) panel displays the mass contours obtained from the WL-only (SL-only) mass map, while the lower panel presents the mass contours derived from the WL + SL mass map. In the WL-only mass map, the contours correspond to ? = [0.15, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8]. For the SL-only and WL + SL mass maps, the contours indicate ? = [0.15, 0.2, 0.3, 0.4, 0.6, 0.9, 1.2, 1.8, 2.4]. To mitigate pixel-scale artifacts, we apply Gaussian smoothing with a kernel of s = 2 '' (s = 1'') to the WL-only (WL + SL) mass contours. In the lower right panel, unsmoothed mass distributions are displayed as a color map. The color-composite images are the same as shown in Figure 1. 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 SL constraint to date for a single cluster. The WL dataset, employing photo-z selection, yields a source density of ~ 350 arcmin-2, marking the densest WL constraint ever. The combined mass reconstruction enables the highest-resolution mass map of Abell 2744 within the ~ 1.8 Mpc×1.8 Mpc reconstruction region to date, revealing the isosceles triangular structure with two legs of ~ 1 Mpc and a base of ~ 0.6 Mpc. Although our algorithm MAximum-entropy ReconStruction (MARS) is entirely blind to the cluster galaxy distribution, the resulting mass reconstruction remarkably well traces the brightest cluster galaxies with the five strongest mass peaks coinciding with the five most luminous cluster galaxies. We do not detect any unusual mass peaks that are not traced by the cluster galaxies, unlike the findings in previous studies. Our mass model shows the smallest scatters 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 MARS represents the mass field with an extremely large number of ~ 300,000 free parameters, it converges to a solution within a few hours thanks to our utilization of the deep learning technique. We make our mass and magnification maps publicly available.