MC²: MAPPING THE DARK MATTER DISTRIBUTION OF THE “TOOTHBRUSH” CLUSTER RX J0603.3+4214 WITH<i>HUBBLE SPACE TELESCOPE</i>AND SUBARU WEAK LENSING

다국어 초록 (Multilingual Abstract)

<P>The galaxy cluster RX J0603.3+4214. at z-0.225 is one of the rarest clusters boasting an extremely large (similar to 2 Mpc) radio. relic. Because of the remarkable morphology of the relic, the cluster is nicknamed the. 'Toothbrush Cluster.' Although the cluster's underlying mass distribution is one of the critical pieces of information needed to reconstruct the merger scenario responsible for the puzzling radio. relic morphology, its proximity to the Galactic plane b similar to 10 degrees has imposed significant observational challenges. We present a high-resolution weak-lensing study of the cluster with Subaru/Suprime Cam and Hubble Space Telescope imaging data. Our mass reconstruction reveals that the cluster is composed of complicated dark matter substructures closely tracing the galaxy distribution, in contrast, however, with the relatively simple binary X-ray morphology. Nevertheless, we find that the cluster mass is still dominated by the two most massive clumps aligned north-south with a similar to 3: 1 mass ratio (M-200 = 6.29(-1.62)(+2.24) x 10(14) M-circle dot and 1.98(-0.74)(+1.24) x 10(14) M-circle dot for the northern and southern clumps, respectively). The southern mass peak is similar to 2' offset toward the south with respect to the corresponding X-ray peak, which has a 'bullet'-like morphology pointing south. Comparison of the current weak-lensing result with the X-ray, galaxy, and radio. relic suggests that perhaps the dominant mechanism responsible for the observed relic may be a highspeed collision of the two most massive subclusters, although the peculiarity of the morphology necessitates involvement of additional subclusters. Careful numerical simulations should follow in order to obtain more complete understanding of the merger scenario utilizing all existing observations.</P>