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arXiv · 1701.01767

The Double Galaxy Cluster Abell 2465 III. X-ray and Weak-lensing Observations

Gary A. Wegner·Keiichi Umetsu·Sandor M. Molnar·Mario Nonino·Elinor Medezinski·Felipe Andrade-Santos·Akos Bogdan·Lorenzo Lovisari·William R. Forman·Christine Jones
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Abstract

We report Chandra X-ray observations and optical weak-lensing measurements from Subaru/Suprime-Cam images of the double galaxy cluster Abell 2465 (z=0.245). The X-ray brightness data are fit to a beta-model to obtain the radial gas density profiles of the northeast (NE) and southwest (SW) sub-components, which are seen to differ in structure. We determine core radii, central temperatures, the gas masses within $r_{500c}$, and the total masses for the broader NE and sharper SW components assuming hydrostatic equilibrium. The central entropy of the NE clump is about two times higher than the SW. Along with its structural properties, this suggests that it has undergone merging on its own. The weak-lensing analysis gives virial masses for each substructure, which compare well with earlier dynamical results. The derived outer mass contours of the SW sub-component from weak lensing are more irregular and extended than those of the NE. Although there is a weak enhancement and small offsets between X-ray gas and mass centers from weak lensing, the lack of large amounts of gas between the two sub-clusters indicates that Abell 2465 is in a pre-merger state. A dynamical model that is consistent with the observed cluster data, based on the FLASH program and the radial infall model, is constructed, where the subclusters currently separated by ~1.2Mpc are approaching each other at ~2000km/s and will meet in ~0.4Gyr.

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Gary A. Wegner, Keiichi Umetsu, Sandor M. Molnar, Mario Nonino, Elinor Medezinski, Felipe Andrade-Santos, Akos Bogdan, Lorenzo Lovisari, William R. Forman, Christine Jones. 2017-01-10. The Double Galaxy Cluster Abell 2465 III. X-ray and Weak-lensing Observations. https://doi.org/10.3847/1538-4357%2Faa784a

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