Abell 315: reconciling cluster mass estimates from kinematics, X-ray, and lensing

Abstract

Determination of cluster masses is a fundamental tool for cosmology. Comparing mass estimates obtained by different probes allows to understand possible systematic uncertainties. The cluster Abell 315 is an interesting test case, since it has been claimed to be underluminous in X-ray for its mass (determined via kinematics and weak lensing). We have undertaken new spectroscopic observations with the aim of improving the cluster mass estimate, using the distribution of galaxies in projected phase space. We identified cluster members in our new spectroscopic sample. We estimated the cluster mass from the projected phase-space distribution of cluster members using the MAMPOSSt method. In doing this estimate we took into account the presence of substructures that we were able to identify. We identify several cluster substructures. The main two have an overlapping spatial distribution, suggesting a (past or ongoing) collision along the line-of-sight. After accounting for the presence of substructures, the mass estimate of Abell 315 from kinematics is reduced by a factor 4, down to M200=0.8 (-0.4,+0.6) x 10^14 Msun. We also find evidence that the cluster mass concentration is unusually low, c200=r200/r-2 <~ 1. Using our new estimate of c200 we revise the weak lensing mass estimate down to M200=1.8 (-0.9,+1.7) x 10^14 Msun. Our new mass estimates are in agreement with that derived from the cluster X-ray luminosity via a scaling relation, M200=0.9+-0.2 x 10^14 Msun. Abell 315 no longer belongs to the class of X-ray underluminous clusters. Its mass estimate was inflated by the presence of an undetected subcluster in collision with the main cluster. Whether the presence of undetected line-of-sight structures can be a general explanation for all X-ray underluminous clusters remains to be explored using a statistically significant sample.

Accepted for publication in A&A. 12 pages, 11 figures

References in corpus (24)

• Concentration, Spin and Shape of Dark Matter Haloes as a Function of the Cosmological Model: WMAP1, WMAP3 and WMAP5 results
• The Canadian Cluster Comparison Project: detailed study of systematics and updated weak lensing masses
• Systematics in the X-ray Cluster Mass Estimators
• CLASH: Weak-Lensing Shear-and-Magnification Analysis of 20 Galaxy Clusters
• The relation between velocity dispersion and mass in simulated clusters of galaxies: dependence on the tracer and the baryonic physics
• The accretion history of dark matter halos III: A physical model for the concentration-mass relation
• On the efficiency and reliability of cluster mass estimates based on member galaxies
• Next Generation Cosmology: Constraints from the Euclid Galaxy Cluster Survey
• Why Do Only Some Galaxy Clusters Have Cool Cores?
• A Statistical Study of Weak Lensing by Triaxial Dark Matter Halos: Consequences for Parameter Estimation
• LoCuSS: Testing hydrostatic equilibrium in galaxy clusters
• The accretion history of dark matter halos II: The connections with the mass power spectrum and the density profile
• The L_X--M relation of Clusters of Galaxies
• The impact of mergers on relaxed X-ray clusters - III. Effects on compact cool cores
• RASS-SDSS Galaxy Cluster Survey. V. The X-ray-Underluminous Abell Clusters
• Orientation Bias of Optically Selected Galaxy Clusters and Its Impact on Stacked Weak Lensing Analyses
• Evolution of Phase-Space Density in Dark Matter Halos
• CoMaLit - II. The scaling relation between mass and Sunyaev-Zel'dovich signal for Planck selected galaxy clusters
• The X-CLASS - redMaPPer galaxy cluster comparison: I. Identification procedures
• Offsets between the X-ray and the Sunyaev-Zel'dovich-effect peaks in merging galaxy clusters and their cosmological implications
• Optical analysis of the poor clusters Abell 610, Abell 725, and Abell 796, containing diffuse radio sources
• LoCuSS: The Near-Infrared Luminosity and Weak-Lensing Mass Scaling Relation of Galaxy Clusters
• The mass profile and dynamical status of the z~0.8 galaxy cluster LCDCS 0504
• Galaxy systems in the optical and infrared

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• The galaxy cluster mass scale and its impact on cosmological constraints from the cluster population
• Mass Calibration of the CODEX Cluster Sample using SPIDERS Spectroscopy -- I. The Richness-Mass Relation
• The GOGREEN survey: the internal dynamics of clusters of galaxies at redshift 0.9-1.4
• Mass Calibration of the CODEX Cluster Sample using SPIDERS Spectroscopy -- II. The X-ray Luminosity-Mass Relation
• Searching for dark matter annihilation from individual halos: uncertainties, scatter and signal-to-noise ratios
• Multiple AGN activity during the BCG assembly of XDCPJ0044.0-2033 at z~1.6
• The Dynamics of the Wide-Angle Tailed (WAT) galaxy cluster Abell 562