The Dark Matter Distribution in the Central Regions of Galaxy Clusters: Implications for Cold Dark Matter

By D. Sand, T. Treu, Graham P. Smith, Richard S. Ellis. 2003

235 citations recorded by the source corpus.

We have undertaken a spectroscopic survey of gravitational arcs in a carefully chosen sample of six clusters, each containing a dominant brightest cluster galaxy. We use these systems to study the relative distributions of dark and baryonic material in the central regions. Three clusters present both radial and tangential arcs and provide particularly strong constraints on the mass profiles, whereas the other three display only tangential arcs and act as a control set. Following Sand, Treu, & Ellis, we analyze stellar velocity dispersion data for the brightest cluster galaxies in conjunction with the arc redshifts and lens models to constrain the dark and baryonic mass profiles jointly. For the systems containing radial arcs we find that the inner dark matter density profile is consistent with a three-dimensional distribution, ρDM ∝ r-β, with logarithmic slope ⟨β⟩ = 0.52 (68% CL). Similarly, we find that the tangential arc sample gives an upper limit, β < 0.57 (99% CL). Taking the six clusters together, the mean dark matter distribution is inconsistent with the standard NFW value, β = 1.0, at greater than 99% confidence. In addition, we find considerable cosmic scatter in the β (Δβ ~ 0.3) values of the radial arc sample. We find no evidence that systems with radial arcs preferentially yield flatter dark matter profiles as might be expected if they were a biased subset. We discuss the validity of our one-dimensional mass reconstruction method and verify its conclusions by comparing with results of a more rigorous ray-tracing code that does not assume axial symmetry. Our results extend and considerably strengthen the earlier conclusions presented by Sand and coworkers and suggest that the relationship between dark and visible matter in the cores of clusters is much more complex than anticipated from recent simulations.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/a6f463244c3a79088ce620f49ec1a5ac232dbab9

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Citations in the corpus

THE LICK AGN MONITORING PROJECT: THE MBH–σ* RELATION FOR REVERBERATION-MAPPED ACTIVE GALAXIES (2010, methodology): “These steps were performed by the IRAF package EASI2D, which was developed by David J. Sand and Tommaso Treu (Sand et al. 2004) for easy extraction of echelle orders.”
THE CLUSTER LENSING AND SUPERNOVA SURVEY WITH HUBBLE: AN OVERVIEW (2011, background): “Some clusters have been shown to have inner mass profiles that are shallower than NFW (Sand et al. 2004, 2008; Newman et al. 2009, 2011).”
HUBBLE SPACE TELESCOPE COMBINED STRONG AND WEAK LENSING ANALYSIS OF THE CLASH SAMPLE: MASS AND MAGNIFICATION MODELS AND SYSTEMATIC UNCERTAINTIES (2014, methodology): “SL features used here were known from previous works, spanning the redshift range z = [1, 6] (e.g., Smith et al. 2001; Sand et al. 2004; Newman et al. 2011; Richard et al. 2011), supplemented with a few other multiple images and candidates found by Zitrin et al. (2011b).”
Cosmological Simulations with Self-Interacting Dark Matter I: Constant Density Cores and Substructure (2012, background): “Sand et al. (2004), Sand et al. (2008) , Newman et al. (2009), and Newman et al. (2011) all find central density profiles in clusters shallower than the NFW CDM prediction.”
A Bayesian approach to strong lensing modelling of galaxy clusters (2007, background): “Observations are not yet giving definitive answers relative to the value of the inner slope (Gavazzi et al. 2003; Sand et al. 2004, 2007) or the concentration (Kneib et al. 2003; Gavazzi et al. 2003), but progress is being made steadily.”
The Sloan Lens ACS Survey. IV. The Mass Density Profile of Early-Type Galaxies out to 100 Effective Radii (2007, unknown): “…those predictions to observations with debated results in the case e.g. of low surface brightness galaxies (Salucci 2001; de Blok et al. 2003; Swaters et al. 2003; Gentile et al. 2004; Simon et al. 2005) or at galaxy cluster scales (e.g. Sand et al. 2004; Gavazzi 2005; Comerford et al. 2006).”
Combining Lens Distortion and Depletion to Map the Mass Distribution of A1689 (2007, background): “From space, deep multi-color images of massive clusters can be used to identify many sets of multiple images per cluster (Broadhurst et al. 2005b, hereafter B05b; Gavazzi et al. 2003; Kneib et al. 2004; Sand et al. 2004; Smith et al. 2005; Bradač et al. 2006).”
Characterizing the Cluster Lens Population (2005, background): “…fit parameters which describe the distribution of dark matter in each cluster lens (e.g. Tyson, Kochanski, & dell’Antonio 1998; Smith et al. 2001; Sand et al. 2004; Broadhurst et al. 2005a), and even stronger constraints can be obtained when strong lensing information is combined with…”
THE DENSITY PROFILES OF MASSIVE, RELAXED GALAXY CLUSTERS. I. THE TOTAL DENSITY OVER THREE DECADES IN RADIUS (2012, methodology): “A383 The model follows N11, which built upon Sand et al. (2004, 2008) and Smith et al. (2005).”
Formation of Galaxy Clusters (2012, background): “…indicate that the slope of the density profile in central regions of some clusters may be shallower than predicted (Newman et al. 2011, 2009; Sand et al. 2008, 2004; Tyson, Kochanski & dell’Antonio 1998), whereas concentrations are considerably higher than both theoretical predictions and…”
Numerical simulations of the dark universe: State of the art and the next decade (2012, background): “of individual halos through cluster and galaxy-galaxy lensing [75, 76], and strong lensing, which can probe the central slope of DM density profiles [77] and is sensitive, through flux ratio anomalies [78] and potentially time-delay perturbations [79], to the amount of DM substructure present in clu”
Small scale problems of the $\Lambda$CDM model: a short review (2016, result): “[209] combining weak lensing, strong lensing, and velocity dispersion studies of the stars of the BCG (Brightest Central Galaxy) found that out of the clusters MACS1206, MS2137-23, RXJ1133, A383, A1201, A963, only RXJ1133 had a profile compatible with the NFW model, and similar studies of Newman et ”
The dark matter haloes of massive, relaxed galaxy clusters observed with Chandra (2006, methodology): “These authors concluded that the strong lensing data of Sand et al. (2002, 2004) remain consistent with CDM models, once such effects are taken into account.”