Detailed Mass Map of CL 0024+1654 from Strong Lensing

We construct a high-resolution mass map of the cluster 00241654, based on a parametric inversionz 0.39 of the associated gravitational lens. The lens creates eight well-resolved subimages of a background galaxy, seen in deep imaging with the Hubble Space Telescope.1 Excluding mass concentrations centered on visible galaxies, more than 98 % of the remaining mass is represented by a smooth concentration of dark matter centered near the brightest cluster galaxies, with a 35 kpc soft core. The asymmetry in the mass distribution is less than 3%1h inside 107 h1 kpc radius. The dark matter distribution we observe in CL 0024 is far more smooth, symmetric, and nonsingular than in typical simulated clusters in either or cold dark matter cosmologies.Q 1 Q 0.3 Integrated to a 107 h1 kpc radius, the rest-frame mass-to-light ratio is M /.L 276 40 h (M/L)V V,