A Precise Cluster Mass Profile Averaged From the Highest-Quality Lensing Data

Abstract

We outline our methods for obtaining high-precision mass profiles, combining independent weak-lensing distortion, magnification, and strong-lensing measurements. For massive clusters, the strong-and weak-lensing regimes contribute equal logarithmic coverage of the radial profile. The utility of high-quality data is limited by the cosmic noise from large-scale structure along the line of sight. This noise is overcome when stacking clusters, as too are the effects of cluster asphericity and substructure, permitting a stringent test of theoretical models. We derive a mean radial mass profile of four similar mass clusters of high-quality Hubble Space Telescope and Subaru images, in the range R = 40-2800 kpc h −1 , where the inner radial boundary is sufficiently large to avoid smoothing from miscentering effects. The stacked mass profile is detected at 58σ significance over the entire radial range, with the contribution from the cosmic noise included. We show that the projected mass profile has a continuously steepening gradient out to beyond the virial radius, in remarkably good agreement with the standard Navarro-Frenk-White form predicted for the family of cold dark matter (CDM) dominated halos in gravitational equilibrium. (at M vir = 1.54 +0.11 −0.10 × 10 15 M h −1 ), which is high for relaxed, high-mass clusters, but consistent with ΛCDM when a sizable projection bias estimated from N-body simulations is considered. This possible tension will be more definitively explored with new cluster surveys, such as CLASH, LoCuSS, Subaru Hyper Suprime-Cam, and XXM-XXL, to construct the c vir -M vir relation over a wider mass range.

Clash: The Enhanced Lensing Efficiency of the Highly Elongated Merging Cluster Macs J0416.1–2403

“…J2000 = −24:04:20.80) of the two models are almost identical throughout the range where multiple images are observed (r < 1 ); see Figure 2. The two models are also in excellent agreement with independent, color-colorselected background galaxies' (Medezinski et al 2010) WL measurements from BR c z Subaru data (Figure 2), using the Bayesian method of Umetsu et al (2011aUmetsu et al ( , 2011b) that combines tangential-distortion and magnification-bias measurements in a Notes. Column 1: arc ID.…”

The Frontier Fields: Survey Design and Initial Results

“…Abell 370 (Abell 1958) at z=0.375 (Struble & Rood 1999) is the host of the first known gravitational Einstein ring (Paczynski 1987;Soucail et al 1987) and thus one of the best studied strong-lensing clusters (e.g., Kneib et al 1993;Smail et al 1996;Bezecourt et al 1999aBezecourt et al , 1999bBroadhurst et al 2008;Medezinski et al 2010;Richard et al 2010;Umetsu et al 2011). Its total velocity dispersion is ∼1170 km s −1 (Dressler et al 1999), with the two main substructures showing internal velocity dispersions of ∼850 km s −1 (Kneib et al 1993).…”

“…15 M e (e.g., Morandi et al 2007;Richard et al 2010;Umetsu et al 2011). With HST ACS images taken shortly after the last HST refurbishment, Richard et al (2010) found significant offsets between the peak X-ray emission and peaks of the lensing mass distribution, and concluded that Abell 370 is likely the recent merger of two equal-mass clusters along the line of sight.…”

LoCuSS: weak-lensing mass calibration of galaxy clusters

“…We do not assume any specific functions of n b because the background distribution is not constant, and may be depleted or boosted by a magnification bias (e.g. Broadhurst, Taylor & Peacock 1995;Umetsu et al 2011Umetsu et al , 2014Coupon, Broadhurst & Umetsu 2013). The second term in the bracket denotes the member galaxy distribution; B is the fraction, f (∆C) is the colour distribution and nm(r) is the radial distribution.…”

“…Stacking the shear signal from a sample of clusters averages over the distribution of internal structures and halo triaxiality, and thus overcomes the structural biases suffered by some individual cluster mass measurements (e.g. Mandelbaum et al 2006;Johnston et al 2007;Okabe et al 2010aOkabe et al , 2013Umetsu et al 2011Umetsu et al , 2014Umetsu et al , 2015bOguri et al 2012;Leauthaud et al 2012;Miyatake et al 2013;Niikura et al 2015). We compute the average lensing signal in physical length unit centered on the respective BCGs.…”