Reconciling concentration to virial mass relations

Abstract

The concentration-virial mass (c-M) relation is a fundamental scaling relation within the standard cold dark matter ($\Lambda$CDM) framework well established in numerical simulations. However, observational constraints of this relation are hampered by the difficulty of characterising the properties of dark matter haloes. Recent comparisons between simulations and observations have suggested a systematic difference of the c-M relation, with higher concentrations in the latter. In this work, we undertake detailed comparisons between simulated galaxies and observations of a sample of strong-lensing galaxies. We explore several factors of the comparison with strong gravitational lensing constraints, including the choice of the generic dark matter density profile, the effect of radial resolution, the reconstruction limits of observed versus simulated mass profiles, and the role of the initial mass function in the derivation of the dark matter parameters. Furthermore, we show the dependence of the c-M relation on reconstruction and model errors through a detailed comparison of real and simulated gravitational lensing systems. An effective reconciliation of simulated and observed c-M relations can be achieved if one considers less strict assumptions on the dark matter profile, for example, by changing the slope of a generic NFW profile or focusing on rather extreme combinations of stellar-to-dark matter distributions. A minor effect is inherent to the applied method: fits to the NFW profile on a less well-constrained inner mass profile yield slightly higher concentrations and lower virial masses.

9 pages, 9 figures, 2 tables. Accepted for publication in A&A

References in corpus (38)

• Galactic Stellar and Substellar Initial Mass Function
• On the variation of the Initial Mass Function
• The EAGLE project: Simulating the evolution and assembly of galaxies and their environments
• Profiles of dark haloes: evolution, scatter, and environment
• Introducing the Illustris Project: Simulating the coevolution of dark and visible matter in the Universe
• The EAGLE simulations of galaxy formation: calibration of subgrid physics and model variations
• Cold dark matter haloes in the Planck era: evolution of structural parameters for Einasto and NFW profiles
• The statistics of LCDM Halo Concentrations
• Concentration, Spin and Shape of Dark Matter Haloes as a Function of the Cosmological Model: WMAP1, WMAP3 and WMAP5 results
• A systematic variation of the stellar initial mass function in early-type galaxies
• The Dependence of Halo Clustering on Halo Formation History, Concentration, and Occupation
• Concentration, Spin and Shape of Dark Matter Haloes: Scatter and the Dependence on Mass and Environment
• A Substantial Population of Low Mass Stars in Luminous Elliptical Galaxies
• Mass and Environment as Drivers of Galaxy Evolution II: The quenching of satellite galaxies as the origin of environmental effects
• The Uchuu Simulations: Data Release 1 and Dark Matter Halo Concentrations
• An accurate physical model for halo concentrations
• The accretion history of dark matter halos III: A physical model for the concentration-mass relation
• Halo mass - concentration relation from weak lensing
• CLASH: The Concentration-Mass Relation of Galaxy Clusters
• Systematic variation of the stellar Initial Mass Function with velocity dispersion in early-type galaxies
• Radial variations in the stellar initial mass function of early-type galaxies
• Empirical calibration of the near-IR CaII triplet - IV. The stellar population synthesis models
• The Observed Concentration-Mass Relation for Galaxy Clusters
• The X-Ray Concentration-Virial Mass Relation
• The SINFONI Nearby Elliptical Lens Locator Survey: Discovery of two new low-redshift strong lenses and implications for the initial mass function in giant early-type galaxies
• IMF shape constraints from stellar populations and dynamics from CALIFA
• Stellar and total mass in early-type lensing galaxies
• IMF radial gradients in most massive early-type galaxies
• Concentrations of Dark Haloes Emerge from Their Merger Histories
• Qualitative Theory for Lensed QSOs
• Strong Gravitational Lensing and the Stellar IMF of Early-type Galaxies
• Bottom-heavy initial mass function in a nearby compact L*-galaxy
• Constraining the low-mass end of the Initial Mass Function with Gravitational Lensing
• Resolving the baryon-fraction profile in lensing galaxies
• Stellar dynamics in the strong-lensing central galaxy of Abell 1201: A low stellar mass-to-light ratio, a large central compact mass, and a standard dark matter halo
• A Sampling Strategy for High-Dimensional Spaces Applied to Free-Form Gravitational Lensing
• Diagnostics of Baryonic Cooling in Lensing Galaxies
• How environment drives galaxy evolution: lessons learnt from satellite galaxies