Dark matter dynamics in Abell 3827: new data consistent with standard Cold Dark Matter
Abstract
We present integral field spectroscopy of galaxy cluster Abell 3827, using ALMA and VLT/MUSE. It reveals an unusual configuration of strong gravitational lensing in the cluster core, with at least seven lensed images of a single background spiral galaxy. Lens modelling based on HST imaging had suggested that the dark matter associated with one of the cluster's central galaxies may be offset. The new spectroscopic data enable better subtraction of foreground light, and better identification of multiple background images. The inferred distribution of dark matter is consistent with being centered on the galaxies, as expected by LCDM. Each galaxy's dark matter also appears to be symmetric. Whilst we do not find an offset between mass and light (suggestive of self-interacting dark matter) as previously reported, the numerical simulations that have been performed to calibrate Abell 3827 indicate that offsets and asymmetry are still worth looking for in collisions with particular geometries. Meanwhile, ALMA proves exceptionally useful for strong lens image identifications.
Cite
@article{arxiv.1708.04245,
title = {Dark matter dynamics in Abell 3827: new data consistent with standard Cold Dark Matter},
author = {Richard Massey and David Harvey and Jori Liesenborgs and Johan Richard and Stuart Stach and Mark Swinbank and Peter Taylor and Liliya Williams and Douglas Clowe and Frederic Courbin and Alastair Edge and Holger Israel and Mathilde Jauzac and Remy Joseph and Eric Jullo and Thomas D. Kitching and Adrienne Leonard and Julian Merten and Daisuke Nagai and James Nightingale and Andrew Robertson and Luis Javier Romualdez and Prasenjit Saha and Renske Smit and Sut Ieng Tam and Eric Tittley},
journal= {arXiv preprint arXiv:1708.04245},
year = {2018}
}
Comments
10 pages, 5 figures. Comments welcome