Zooming into the Cosmic Horseshoe: new insights on the lens profile and the source shape

Abstract

The gravitational lens SDSS J1148+1930, also known as the Cosmic Horseshoe, is one of the biggest and of the most detailed Einstein rings ever observed. We use the forward reconstruction method implemented in the lens fitting code Lensed to investigate with great detail the properties of the lens and of the background source. We model the lens with different mass distributions, focusing in particular on the determination of the slope of the dark matter component. The inherent degeneracy between the lens slope and the source size can be broken when we can isolate separate components of each lensed image, as in this case. For an elliptical power law model, $\kappa (r)\sim r^{-t}$, the results favour a flatter-than-isothermal slope with a maximum-likelihood value t = 0.08. Instead, when we consider the contribution of the baryonic matter separately, the maximum-likelihood value of the slope of the dark matter component is t = 0.31 or t = 0.44, depending on the assumed Initial Mass Function. We discuss the origin of this result by analysing in detail how the images and the sources change when the slope t changes. We also demonstrate that these slope values at the Einstein radius are not inconsistent with recent forecast from the theory of structure formation in the LambdaCDM model.

arXiv comment13 pages, 9 figures, accepted for publication in MNRAS

References in corpus (50)

• A Universal Density Profile from Hierarchical Clustering
• MultiNest: an efficient and robust Bayesian inference tool for cosmology and particle physics
• Multimodal nested sampling: an efficient and robust alternative to MCMC methods for astronomical data analysis
• The Structure of Dark Matter Haloes in Dwarf Galaxies
• Constraints on the relationship between stellar mass and halo mass at low and high redshift
• The Inner Structure of LambdaCDM Halos III: Universality and Asymptotic Slopes
• Importance Nested Sampling and the MultiNest Algorithm
• The Dark Side of the Halo Occupation Distribution
• A Bayesian approach to strong lensing modelling of galaxy clusters
• The Sloan Lens ACS Survey. X. Stellar, Dynamical, and Total Mass Correlations of Massive Early-type Galaxies
• The Sloan Lens ACS Survey. I. A Large Spectroscopically Selected Sample of Massive Early-Type Lens Galaxies
• Accurate universal models for the mass accretion histories and concentrations of dark matter halos
• Cold dark matter: controversies on small scales
• The Observed properties of Dark Matter on small spatial scales
• Dissecting the Gravitational Lens B1608+656. II. Precision Measurements of the Hubble Constant, Spatial Curvature, and the Dark Energy Equation of State
• Density Profiles of Dark Matter Halo are not Universal
• Baryon effects on the internal structure of LCDM halos in the EAGLE simulations
• The Mass-Concentration-Redshift Relation of Cold and Warm Dark Matter Halos
• Cold dark matter heats up
• Detection of a Dark Substructure through Gravitational Imaging
• The Density Profiles of Massive, Relaxed Galaxy Clusters. II. Separating Luminous and Dark Matter in Cluster Cores
• Semi-linear gravitational lens inversion
• Halo mass - concentration relation from weak lensing
• The SL2S Galaxy-scale Lens Sample. IV. The dependence of the total mass density profile of early-type galaxies on redshift, stellar mass, and size
• The dark matter density profile of the lensing cluster MS2137-23: a test of the cold dark matter paradigm
• The Sloan Lens ACS Survey. VI: Discovery and analysis of a double Einstein ring
• Halo Cores and Phase Space Densities: Observational Constraints on Dark Matter Physics and Structure Formation
• The Redshift Evolution of LCDM Halo Parameters: Concentration, Spin, and Shape
• The internal structure of the lens PG1115+080: breaking degeneracies in the value of the Hubble Constant
• Evidence for dark matter contraction and a Salpeter IMF in a massive early-type galaxy
• The Origin and Evolution of Metallicity Gradients: Probing the Mode of Mass Assembly at z=2
• Source-position transformation -- an approximate invariance in strong gravitational lensing
• The Ultraviolet Spectrum of the Gravitationally Lensed Galaxy `The Cosmic Horseshoe': A Close-up of a Star-forming Galaxy at z = 2
• The stellar and dark matter distributions in elliptical galaxies from the ensemble of strong gravitational lenses
• The mass-sheet degeneracy and time-delay cosmography: Analysis of the strong lens RXJ1131-1231
• The Cosmic Horseshoe: Discovery of an Einstein Ring around a Giant Luminous Red Galaxy
• Small scatter and nearly-isothermal mass profiles to four half-light radii from two-dimensional stellar dynamics of early-type galaxies
• Formation times, mass growth histories and concentrations of dark matter haloes
• The X-Shooter Lens Survey - I. Dark-Matter Domination and a Salpeter-type IMF in a Massive Early-type Galaxy
• Models of the Cosmic Horseshoe Gravitational Lens
• Super-resolving distant galaxies with gravitational telescopes: Keck-LGSAO and Hubble imaging of the lens system SDSSJ0737+3216
• The elliptical power law profile lens
• A Unifying Framework for Self-consistent Gravitational Lensing and Stellar Dynamics Analyses of Early-Type Galaxies
• Cosmography from two-image lens systems: overcoming the lens profile slope degeneracy
• Strong Gravitational Lensing and the Stellar IMF of Early-type Galaxies
• Modelling mass distribution in elliptical galaxies: mass profiles and their correlation with velocity dispersion profiles
• Lensed: a code for the forward reconstruction of lenses and sources from strong lensing observations
• The evolution of late-type galaxies from CASSOWARY lensing systems
• Lensing and Dynamics in Two Simple Steps
• Golden gravitational lensing systems from the Sloan Lens ACS Survey. II. SDSS J1430+4105: A precise inner total mass profile from lensing alone

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• The Strong Gravitational Lens Finding Challenge
• The inner dark matter distribution of the Cosmic Horseshoe (J1148+1930) with gravitational lensing and dynamics
• Strong lensing in UNIONS: Toward a pipeline from discovery to modeling
• SEAGLE - I: A pipeline for simulating and modeling strong lenses from cosmological hydrodynamic simulations
• Sparse Lens Inversion Technique (SLIT): lens and source separability from linear inversion of the source reconstruction problem
• SEAGLE--II: Constraints on feedback models in galaxy formation from massive early type strong lens galaxies
• An accurate analytic mass model for lensing galaxies
• Galaxy mass profiles from strong lensing I: The circular power-law model
• The dynamical structure of broken power-law and double power-law models for dark matter haloes
• Pixelated Reconstruction of Foreground Density and Background Surface Brightness in Gravitational Lensing Systems using Recurrent Inference Machines
• SEAGLE--III: Towards resolving the mismatch in the dark-matter fraction in early-type galaxies between simulations and observations
• Lessons from a blind study of simulated lenses: image reconstructions do not always reproduce true convergence
• Relativistic effects cannot explain galactic dynamics
• Lensed stars in galaxy-galaxy strong lensing -- a JWST prediction for the Cosmic Horseshoe