516 citations · 2.1k across the 32 of their papers we have counts for
25 papers · 1 filter
Strong gravitational lensing's 'external shear' is not shear
Amy Etherington, James W. Nightingale, Richard Massey +19
The distribution of mass in galaxy-scale strong gravitational lenses is often modelled as an elliptical power law plus 'external shear', which notionally accounts for neighbouring…
Constraints on dark matter self-interaction from the internal density profiles of X-COP galaxy clusters
D. Eckert, S. Ettori, A. Robertson +4
TThe fundamental properties of the postulated dark matter (DM) affect the internal structure of gravitationally-bound structures. In the cold dark matter paradigm, DM particles int…
The impact of Self-Interacting Dark Matter on the Intrinsic Alignments of Galaxies
David Harvey, Nora Elisa Chisari, Andrew Robertson +1
The formation and evolution of galaxies is known to be sensitive to tidal processes leading to intrinsic correlations between their shapes and orientations. Such correlations can b…
A 4% measurement of using the cumulative distribution of strong-lensing time delays in doubly-imaged quasars
David Harvey
In the advent of large scale surveys, individually modelling strong-gravitational lenses and their counterpart time-delays in order to precisely measure will become computati…
Reconciling galaxy cluster shapes, measured by theorists vs observers
David Harvey, Andrew Robertson, Sut-Ieng Tam +4
If properly calibrated, the shapes of galaxy clusters can be used to investigate many physical processes: from feedback and quenching of star formation, to the nature of dark matte…
The distribution of dark matter and gas spanning six megaparsecs around the post-merger galaxy cluster MS0451-03
Sut-Ieng Tam, Mathilde Jauzac, Richard Massey +11
Using the largest mosaic of Hubble Space Telescope images around a galaxy cluster, we map the distribution of dark matter throughout a Mpc area centred on the…
From dwarf galaxies to galaxy clusters: Self-Interacting Dark Matter over 7 orders of magnitude in halo mass
Kyrylo Bondarenko, Anastasia Sokolenko, Alexey Boyarsky +3
In this paper we study the density profiles of self-interacting dark matter (SIDM) haloes spanning the full observable mass range, from dwarf galaxies to galaxy clusters. Using rea…
Exploiting flux ratio anomalies to probe warm dark matter in future large scale surveys
David Harvey, Wessel Valkenburg, Amelie Tamone +3
Flux ratio anomalies in strong gravitationally lensed quasars constitute a unique way to probe the abundance of non-luminous dark matter haloes, and hence the nature of dark matter…
The shape of relaxed galaxy clusters and the public release of a HST shape measurement code, pyRRG
David Harvey, Sut-Ieng Tam, Mathilde Jauzac +2
We study the shape of eight dynamically relaxed galaxy clusters observed with the Hubble Space Telescope and Chandra X-Ray Observatory. Using strong and weak gravitational lensing,…
Observable tests of self-interacting dark matter in galaxy clusters: BCG wobbles in a constant density core
David Harvey, Andrew Robertson, Richard Massey +1
Models of Cold Dark Matter predict that the distribution of dark matter in galaxy clusters should be cuspy, centrally concentrated. Constant density cores would be strong evidence…
Observable tests of self-interacting dark matter in galaxy clusters: cosmological simulations with SIDM and baryons
Andrew Robertson, David Harvey, Richard Massey +5
We present BAHAMAS-SIDM, the first large-volume, (400/h Mpc)^3, cosmological simulations including both self-interacting dark matter (SIDM) and baryonic physics. These simulations…
The shape of galaxy dark matter halos in massive galaxy clusters: Insights from strong gravitational lensing
M. Jauzac, D. Harvey, R. Massey
We assess how much unused strong lensing information is available in the deep \emph{Hubble Space Telescope} imaging and VLT/MUSE spectroscopy of the \emph{Frontier Field} clusters.…
Dark matter dynamics in Abell 3827: new data consistent with standard Cold Dark Matter
Richard Massey, David Harvey, Jori Liesenborgs +23
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 cor…
A detection of wobbling Brightest Cluster Galaxies within massive galaxy clusters
David Harvey, F. Courbin, J. P. Kneib +1
A striking signal of dark matter beyond the standard model is the existence of cores in the centre of galaxy clusters. Recent simulations predict that a Brightest Cluster Galaxy (B…
A test for skewed distributions of dark matter and a possible detection in galaxy cluster Abell 3827
Peter Taylor, Richard Massey, Mathilde Jauzac +4
Simulations of self-interacting dark matter (SIDM) predict that dark matter should lag behind galaxies during a collision. If the interaction is mediated by a high-mass force carri…
Abell 2744: Too much substructure for Lambda CDM?
J. Schwinn, M. Jauzac, C. M. Baugh +5
The massive substructures found in Abell 2744 by Jauzac et al. (2016) present a challenge to the cold dark matter paradigm due to their number and proximity to the cluster centre.…
Looking for dark matter trails in colliding galaxy clusters
David Harvey, Andrew Robertson, Richard Massey +1
If dark matter interacts, even weakly, via non-gravitational forces, simulations predict that it will be preferentially scattered towards the trailing edge of the halo during colli…
The Extraordinary Amount of Substructure in the Hubble Frontier Fields Cluster Abell 2744
M. Jauzac, D. Eckert, J. Schwinn +21
We present a joint optical/X-ray analysis of the massive galaxy cluster Abell 2744 (z=0.308). Our strong- and weak-lensing analysis within the central region of the cluster, i.e.,…
Systematic or Signal? How dark matter misalignments can bias strong lensing models of galaxy clusters
David Harvey, Jean-Paul Kneib, Mathilde Jauzac
We explore how assuming that mass traces light in strong gravitational lensing models can lead to systematic errors in the predicted position of multiple images. Using a model base…
The behaviour of dark matter associated with 4 bright cluster galaxies in the 10kpc core of Abell 3827
Richard Massey, Liliya Williams, Renske Smit +20
Galaxy cluster Abell 3827 hosts the stellar remnants of four almost equally bright elliptical galaxies within a core of radius 10kpc. Such corrugation of the stellar distribution i…
The non-gravitational interactions of dark matter in colliding galaxy clusters
David Harvey, Richard Massey, Thomas Kitching +2
Collisions between galaxy clusters provide a test of the non-gravitational forces acting on dark matter. Dark matter's lack of deceleration in the `bullet cluster collision' constr…
Hubble Frontier Fields: The Geometry and Dynamics of the Massive Galaxy Cluster Merger MACSJ0416.1-2403
Mathilde Jauzac, Eric Jullo, Dominique Eckert +13
We use a joint optical/X-ray analysis to constrain the geometry and history of the ongoing merging event in the massive galaxy cluster MACSJ0416.1-2403 (z=0.397). Our investigation…
On the cross-section of Dark Matter using substructure infall into galaxy clusters
David Harvey, Eric Tittley, Richard Massey +6
We develop a statistical method to measure the interaction cross-section of Dark Matter, exploiting the continuous minor merger events in which small substructures fall into galaxy…
Dark Matter Astrometry: Accuracy of sub-halo positions for the measurement of self-interaction cross sections
David Harvey, Richard Massey, Thomas Kitching +5
Direct evidence for the existence of dark matter and measurements of its interaction cross-section have been provided by the physical offset between dark matter and intra- cluster…