Discovery of a Dissociative Galaxy Cluster Merger with Large Physical Separation
Abstract
We present DLSCL J0916.2+2951 (z=0.53), a newly discovered major cluster merger in which the collisional cluster gas has become dissociated from the collisionless galaxies and dark matter. We identified the cluster using optical and weak lensing observations as part of the Deep Lens Survey. Our follow-up observations with Keck, Subaru, Hubble Space Telescope, and Chandra show that the cluster is a dissociative merger and constrain the dark matter self-interaction cross-section {\sigma}_{DM}m_{DM}^{-1}\leq7 cm^2g^{-1}. The system is observed at least 0.7\pm0.2 Gyr since first pass-through, thus providing a picture of cluster mergers 2-5 times further progressed than similar systems observed to date. This improved temporal leverage has implications for our understanding of merging clusters and their impact on galaxy evolution.
Keywords
Cite
@article{arxiv.1110.4391,
title = {Discovery of a Dissociative Galaxy Cluster Merger with Large Physical Separation},
author = {William A. Dawson and David Wittman and Myungkook Jee and Perry Gee and John P. Hughes and J. Anthony Tyson and Samuel Schmidt and Paul Thorman and Marusa Bradac and Satoshi Miyazaki and Brian Lemaux and Yousuke Utsumi and Vera E. Margoniner},
journal= {arXiv preprint arXiv:1110.4391},
year = {2012}
}
Comments
Accepted ApJ Letters. [v2] changes: 1 new figure (2b), figure 3 made color, and minor improvements to the text. 6 pages, 4 figures, 1 table