THE DENSITY PROFILES OF MASSIVE, RELAXED GALAXY CLUSTERS. I. THE TOTAL DENSITY OVER THREE DECADES IN RADIUS

By A. Newman, T. Treu, Richard S. Ellis, D. Sand, C. Nipoti, J. Richard, E. Jullo. 2012

207 citations recorded by the source corpus.

Clusters of galaxies are excellent locations to probe the distribution of baryons and dark matter (DM) over a wide range of scales. We study a sample of seven massive (M200 = 0.4–2 × 1015 M☉), relaxed galaxy clusters with centrally located brightest cluster galaxies (BCGs) at z = 0.2–0.3. Using the observational tools of strong and weak gravitational lensing, combined with resolved stellar kinematics within the BCG, we measure the total radial density profile, comprising both dark and baryonic matter, over scales of ≃ 3–3000 kpc. We present Keck spectroscopy yielding seven new spectroscopic redshifts of multiply imaged sources and extended stellar velocity dispersion profiles of the BCGs. Lensing-derived mass profiles typically agree with independent X-ray estimates within ≃ 15%, suggesting that departures from hydrostatic equilibrium are small and that the clusters in our sample (except A383) are not strongly elongated or compressed along the line of sight. The inner logarithmic slope γtot of the total density profile measured over r/r200 = 0.003–0.03, where , is found to be nearly universal, with a mean 〈γtot〉 = 1.16 ± 0.05(random)+0.05−0.07 (systematic) and an intrinsic scatter σγ < 0.13 (68% confidence). This is further supported by the very homogeneous shape of the observed velocity dispersion profiles, which are mutually consistent after a simple scaling. Remarkably, this slope agrees closely with high-resolution numerical simulations that contain only DM, despite the significant contribution of stellar mass on the scales we probe. The Navarro–Frenk–White profile characteristic of collisionless cold DM is a better description of the total mass density at radii ≳ 5–10 kpc than that of DM alone. Hydrodynamical simulations that include baryons, cooling, and feedback currently provide a poorer match. We discuss the significance of our findings for understanding the physical processes governing the assembly of BCGs and cluster cores, particularly the influence of baryons on the inner DM halo.

Subfields: Astronomy and Astrophysics, Instrumentation, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/42913a3d85c56180b1f25a70226a7c5049003e6f

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Citations in the corpus

HUBBLE SPACE TELESCOPE COMBINED STRONG AND WEAK LENSING ANALYSIS OF THE CLASH SAMPLE: MASS AND MAGNIFICATION MODELS AND SYSTEMATIC UNCERTAINTIES (2014, methodology): “Three secure multipleimage systems are known for this cluster, and we follow here the SL constraints (including revised redshifts) as given in Newman et al. (2013b).”
Structure and Kinematics of Early-Type Galaxies from Integral Field Spectroscopy (2016, background): “A broadly consistent systematic trend was obtained by combining strong and weak lensing for massive galaxy clusters (Newman et al. 2013a, 2015).”
The masses and density profiles of halos in a LCDM galaxy formation simulation (2014, result): “Such tests, however, tend to compare observations of haloes which have galaxies within them with results from simulations of pure DM haloes (Newman et al. 2013).”
CLASH: WEAK-LENSING SHEAR-AND-MAGNIFICATION ANALYSIS OF 20 GALAXY CLUSTERS (2014, background): “…by Wright & Brainerd (2000), which provides a sufficiently good description of the projected total matter distribution in cluster-sized halos out to the virial radius rvir (Oguri & Hamana 2011; Umetsu et al. 2011a; Oguri et al. 2012; Newman et al. 2013; Okabe et al. 2013, see also Section 3.2).”
FORTY-SEVEN MILKY WAY-SIZED, EXTREMELY DIFFUSE GALAXIES IN THE COMA CLUSTER (2014, methodology): “Using the mass profile of Abell 2667 (Newman et al. 2013) as a proxy for that of Coma, we findmtot & 3×109 M⊙, or a dark matter fraction within the tidal radiusof & 98 %.”
CLASH-VLT: The mass, velocity-anisotropy, and pseudo-phase-space density profiles of the z = 0.44 galaxy cluster MACS J1206.2-0847 (2013, background): “…et al. 2006b; Rines & Diaferio 2006; Buote et al. 2007; Schmidt & Allen 2007; Biviano 2008; Ettori et al. 2010; Okabe et al. 2010; Oguri et al. 2012; Newman et al. 2012) and that obtained inΛCDM cosmological simulations (e.g. Navarro et al. 1997; Bullock et al. 2001; Duffy et al. 2008; Gao et al.…”
The Frontier Fields lens modelling comparison project (2016, methodology): “…tracers of the cluster gravitational potential, such as weak lensing, galaxy kinematics, and the X-ray emission from the Intra-Cluster-Medium (see e.g., Bradač et al. 2005; Donnarumma et al. 2011; Medezinski et al. 2013; Newman et al. 2013; Umetsu 2013; Umetsu et al. 2014; Merten et al. 2015).”
Mapping stellar content to dark matter haloes using galaxy clustering and galaxy–galaxy lensing in the SDSS DR7 (2015, background): “…baryon and dark matter combined) still maintains a NFW shape from the scales of the central brightest cluster galaxy (BCG) out to the virial radius (Newman et al. 2013), probably due to the significant mixing between stars and dark matter as a result of frequent mergers (Laporte & White 2014).”
Relativistic MHD simulations of core-collapse GRB jets: 3D instabilities and magnetic dissipation (2015, background): “100 kpc) and steepen to ρa ∝ r−2 further out (e.g. Newman et al. 2013).”
The impact of baryonic physics on the structure of dark matter haloes: the view from the FIRE cosmological simulations (2015, background): “Nevertheless, stellar kinematics and strong lensing do suggest cores in galaxy clusters with α ∼ −0.5 (Newman et al. 2013b,a).”