scholarly journals TDCOSMO

2020 ◽  
Vol 643 ◽  
pp. A165 ◽  
Author(s):  
S. Birrer ◽  
A. J. Shajib ◽  
A. Galan ◽  
M. Millon ◽  
T. Treu ◽  
...  
Keyword(s):  
Density Profile ◽  
Gravitational Lensing ◽  
Mass Density ◽  
Hubble Constant ◽  
Potential Effect ◽  
Hierarchical Analysis ◽  
Stellar Kinematics ◽  
Density Profiles ◽  
Mass Profile ◽  
Mass Density Profile

The H0LiCOW collaboration inferred via strong gravitational lensing time delays a Hubble constant value of H0 = 73.3−1.8+1.7 km s−1 Mpc−1, describing deflector mass density profiles by either a power-law or stars (constant mass-to-light ratio) plus standard dark matter halos. The mass-sheet transform (MST) that leaves the lensing observables unchanged is considered the dominant source of residual uncertainty in H0. We quantify any potential effect of the MST with a flexible family of mass models, which directly encodes it, and they are hence maximally degenerate with H0. Our calculation is based on a new hierarchical Bayesian approach in which the MST is only constrained by stellar kinematics. The approach is validated on mock lenses, which are generated from hydrodynamic simulations. We first applied the inference to the TDCOSMO sample of seven lenses, six of which are from H0LiCOW, and measured H0 = 74.5−6.1+5.6 km s−1 Mpc−1. Secondly, in order to further constrain the deflector mass density profiles, we added imaging and spectroscopy for a set of 33 strong gravitational lenses from the Sloan Lens ACS (SLACS) sample. For nine of the 33 SLAC lenses, we used resolved kinematics to constrain the stellar anisotropy. From the joint hierarchical analysis of the TDCOSMO+SLACS sample, we measured H0 = 67.4−3.2+4.1 km s−1 Mpc−1. This measurement assumes that the TDCOSMO and SLACS galaxies are drawn from the same parent population. The blind H0LiCOW, TDCOSMO-only and TDCOSMO+SLACS analyses are in mutual statistical agreement. The TDCOSMO+SLACS analysis prefers marginally shallower mass profiles than H0LiCOW or TDCOSMO-only. Without relying on the form of the mass density profile used by H0LiCOW, we achieve a ∼5% measurement of H0. While our new hierarchical analysis does not statistically invalidate the mass profile assumptions by H0LiCOW – and thus the H0 measurement relying on them – it demonstrates the importance of understanding the mass density profile of elliptical galaxies. The uncertainties on H0 derived in this paper can be reduced by physical or observational priors on the form of the mass profile, or by additional data.

scholarly journals CLASH-VLT: a full dynamical reconstruction of the mass profile of Abell S1063 from 1 kpc out to the virial radius

2020 ◽  
Vol 637 ◽  
pp. A34 ◽  
Author(s):  
B. Sartoris ◽  
A. Biviano ◽  
P. Rosati ◽  
A. Mercurio ◽  
C. Grillo ◽  
...  
Keyword(s):  
Dark Matter ◽  
Density Profile ◽  
Velocity Dispersion ◽  
Mass Density ◽  
Dynamical Analysis ◽  
Cluster Galaxy ◽  
Data Set ◽  
Density Profiles ◽  
Dispersion Profile ◽  
Mass Profile

Context. The shape of the mass density profiles of cosmological halos informs us of the nature of dark matter (DM) and DM-baryons interactions. Previous estimates of the inner slope of the mass density profiles of clusters of galaxies are in opposition to predictions derived from numerical simulations of cold dark matter (CDM). Aims. We determine the inner slope of the DM density profile of a massive cluster of galaxies, Abell S1063 (RXC J2248.7−4431) at z = 0.35, with a dynamical analysis based on an extensive spectroscopic campaign carried out with the VIMOS and MUSE spectrographs at the ESO VLT. This new data set provides an unprecedented sample of 1234 spectroscopic members, 104 of which are located in the cluster core (R ≲ 200 kpc), extracted from the MUSE integral field spectroscopy. The latter also allows the stellar velocity dispersion profile of the brightest cluster galaxy (BCG) to be measured out to 40 kpc. Methods. We used an upgraded version of the MAMPOSSt technique to perform a joint maximum likelihood fit to the velocity dispersion profile of the BCG and to the velocity distribution of cluster member galaxies over a radial range from 1 kpc to the virial radius (r200 ≈ 2.7 Mpc). Results. We find a value of γDM = 0.99 ± 0.04 for the inner logarithmic slope of the DM density profile after marginalizing over all the other parameters of the mass and velocity anisotropy models. Moreover, the newly determined dynamical mass profile is found to be in excellent agreement with the mass density profiles obtained from the independent X-ray hydrostatic analysis based on deep Chandra data, as well as the strong and weak lensing analyses. Conclusions. Our value of the inner logarithmic slope of the DM density profile γDM is in very good agreement with predictions from cosmological CDM simulations. We will extend our analysis to more clusters in future works. If confirmed on a larger cluster sample, our result makes this DM model more appealing than alternative models.

scholarly journals Testing the gas mass density profile of galaxy clusters with distance duality relation

2016 ◽  
Vol 457 (1) ◽  
pp. 281-287 ◽  
Author(s):  
Shuo Cao ◽  
Marek Biesiada ◽  
Xiaogang Zheng ◽  
Zong-Hong Zhu
Keyword(s):  
Galaxy Clusters ◽  
Density Profile ◽  
Mass Density ◽  
Duality Relation ◽  
Mass Density Profile

scholarly journals The intracluster light as a tracer of the total matter density distribution: a view from simulations

2020 ◽  
Vol 494 (2) ◽  
pp. 1859-1864 ◽  
Author(s):  
Isaac Alonso Asensio ◽  
Claudio Dalla Vecchia ◽  
Yannick M Bahé ◽  
David J Barnes ◽  
Scott T Kay
Keyword(s):  
Mass Density ◽  
Radial Profile ◽  
Stellar Mass ◽  
Matter Density ◽  
Density Profiles ◽  
Radial Profiles ◽  
Intracluster Light ◽  
Baryonic Mass ◽  
Mass Density Profile ◽  
Total Matter

ABSTRACT By using deep observations of clusters of galaxies, it has been recently found that the projected stellar mass density closely follows the projected total (dark and baryonic) mass density within the innermost ∼140 kpc. In this work, we aim to test these observations using the Cluster-EAGLE simulations, comparing the projected densities inferred directly from the simulations. We compare the iso-density contours using the procedure of Montes & Trujillo, and find that the shape of the stellar mass distribution follows that of the total matter even more closely than observed, although their radial profiles differ substantially. The ratio between stellar and total matter density profiles in circular apertures shows a slope close to −1, with a small dependence on the cluster’s total mass. We propose an indirect method to calculate the halo mass and mass density profile from the radial profile of the intracluster stellar mass density.

scholarly journals Assessing the effect of lens mass model in cosmological application with updated galaxy-scale strong gravitational lensing sample

2019 ◽  
Vol 488 (3) ◽  
pp. 3745-3758 ◽  
Author(s):  
Yun Chen ◽  
Ran Li ◽  
Yiping Shu ◽  
Xiaoyue Cao
Keyword(s):  
Density Profile ◽  
Gravitational Lensing ◽  
Mass Density ◽  
Cosmological Parameters ◽  
Mass Model ◽  
Surface Mass ◽  
Cosmological Application ◽  
Surface Mass Density ◽  
Resolution Imaging ◽  
Lens Galaxies

ABSTRACT By comparing the dynamical and lensing masses of early-type lens galaxies, one can constrain both the cosmological parameters and the density profiles of galaxies. We explore the constraining power on cosmological parameters and the effect of the lens mass model in this method with 161 galaxy-scale strong lensing systems, which is currently the largest sample with both high-resolution imaging and stellar dynamical data. We assume a power-law mass model for the lenses, and consider three different parametrizations for γ (i.e. the slope of the total mass density profile) to include the effect of the dependence of γ on redshift and surface mass density. When treating δ (i.e. the slope of the luminosity density profile) as a universal parameter for all lens galaxies, we find the limits on the cosmological parameter Ωm are quite weak and biased, and also heavily dependent on the lens mass model in the scenarios of parametrizing γ with three different forms. When treating δ as an observable for each lens, the unbiased estimate of Ωm can be obtained only in the scenario of including the dependence of γ on both the redshift and the surface mass density, that is $\Omega _\mathrm{ m} = 0.381^{+0.185}_{-0.154}$ at 68 per cent confidence level in the framework of a flat ΛCDM model. We conclude that the significant dependencies of γ on both the redshift and the surface mass density, as well as the intrinsic scatter of δ among the lenses, need to be properly taken into account in this method.

scholarly journals 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

2013 ◽  
Vol 777 (2) ◽  
pp. 98 ◽  
Author(s):  
Alessandro Sonnenfeld ◽  
Tommaso Treu ◽  
Raphaël Gavazzi ◽  
Sherry H. Suyu ◽  
Philip J. Marshall ◽  
...  
Keyword(s):  
Density Profile ◽  
Total Mass ◽  
Mass Density ◽  
Stellar Mass ◽  
Early Type ◽  
Mass Density Profile

scholarly journals Cosmology with the submillimetre galaxies magnification bias: Proof of concept

2020 ◽  
Vol 639 ◽  
pp. A128
Author(s):  
L. Bonavera ◽  
J. González-Nuevo ◽  
M. M. Cueli ◽  
T. Ronconi ◽  
M. Migliaccio ◽  
...  
Keyword(s):  
Gravitational Lensing ◽  
Cross Correlation ◽  
Mass Density ◽  
Cosmological Parameters ◽  
Monte Carlo Analysis ◽  
Model Description ◽  
Proof Of Concept ◽  
Photometric Redshifts ◽  
Density Profiles ◽  
Background Sample

Context. As recently demonstrated, high-z submillimetre galaxies (SMGs) are the perfect background sample for tracing the mass density profiles of galaxies and clusters (baryonic and dark matter) and their time-evolution through gravitational lensing. Their magnification bias, a weak gravitational lensing effect, is a powerful tool for constraining the free parameters of a halo occupation distribution (HOD) model and potentially also some of the main cosmological parameters. Aims. The aim of this work is to test the capability of the magnification bias produced on high-z SMGs as a cosmological probe. We exploit cross-correlation data to constrain not only astrophysical parameters (Mmin, M1, and α), but also some of the cosmological ones (Ωm, σ8, and H0) for this proof of concept. Methods. The measured cross-correlation function between a foreground sample of GAMA galaxies with spectroscopic redshifts in the range 0.2 < z < 0.8 and a background sample of H-ATLAS galaxies with photometric redshifts > 1.2 is modelled using the traditional halo model description that depends on HOD and cosmological parameters. These parameters are then estimated by performing a Markov chain Monte Carlo analysis using different sets of priors to test the robustness of the results and to study the performance of this novel observable with the current set of data. Results. With our current results, Ωm and H0 cannot be well constrained. However, we can set a lower limit of > 0.24 at 95% confidence level (CL) on Ωm and we see a slight trend towards H0 >  70 values. For our constraints on σ8 we obtain only a tentative peak around 0.75, but an interesting upper limit of σ8 ≲ 1 at 95% CL. We also study the possibility to derive better constraints by imposing more restrictive priors on the astrophysical parameters.

scholarly journals Testing the cosmic curvature at high redshifts: the combination of LSST strong lensing systems and quasars as new standard candles

2020 ◽  
Vol 496 (1) ◽  
pp. 708-717 ◽  
Author(s):  
Tonghua Liu ◽  
Shuo Cao ◽  
Jia Zhang ◽  
Marek Biesiada ◽  
Yuting Liu ◽  
...  
Keyword(s):  
Power Law ◽  
Density Profile ◽  
Mass Density ◽  
Model Parameters ◽  
Fundamental Parameter ◽  
Lens Model ◽  
Sis Model ◽  
Stringent Constraint ◽  
Strong Lensing ◽  
Mass Density Profile

ABSTRACT The cosmic curvature, a fundamental parameter for cosmology could hold deep clues to inflation and cosmic origins. We propose an improved model-independent method to constrain the cosmic curvature by combining the constructed Hubble diagram of high-redshift quasars with galactic-scale strong lensing systems expected to be seen by the forthcoming Large Synoptic Survey Telescope survey. More specifically, the most recent quasar data are used as a new type of standard candles in the range 0.036 &lt; z &lt; 5.100, whose luminosity distances can be directly derived from the non-linear relation between X-ray and UV luminosities. Compared with other methods, the proposed one involving the quasar data achieves constraints with higher precision (ΔΩk ∼ 10−2) at high redshifts (z ∼ 5.0). We also investigate the influence of lens mass distribution in the framework of three types of lens models extensively used in strong lensing studies (SIS model, power-law spherical model, and extended power-law lens model), finding the strong correlation between the cosmic curvature and the lens model parameters. When the power-law mass density profile is assumed, the most stringent constraint on the cosmic curvature Ωk can be obtained. Therefore, the issue of mass density profile in the early-type galaxies is still a critical one that needs to be investigated further.

scholarly journals The Sloan Lens ACS Survey. IV. The Mass Density Profile of Early‐Type Galaxies out to 100 Effective Radii

2007 ◽  
Vol 667 (1) ◽  
pp. 176-190 ◽  
Author(s):  
Raphael Gavazzi ◽  
Tommaso Treu ◽  
Jason D. Rhodes ◽  
Leon V. E. Koopmans ◽  
Adam S. Bolton ◽  
...  
Keyword(s):  
Density Profile ◽  
Mass Density ◽  
Early Type ◽  
Mass Density Profile

scholarly journals Self-gravitating dark matter gets in shape

2020 ◽  
Vol 29 (14) ◽  
pp. 2043017
Author(s):  
Jenny Wagner
Keyword(s):  
Dark Matter ◽  
Gravitational Lensing ◽  
Spatial Configuration ◽  
Mass Density ◽  
Gravitational Interaction ◽  
Mathematical Approach ◽  
Density Profiles ◽  
Physical Methods ◽  
The Universe ◽  
Galaxy Rotation Curves

In our current best cosmological model, the vast majority of matter in the universe is dark, consisting of yet undetected, nonbaryonic particles that do not interact electro-magnetically. So far, the only significant evidence for dark matter has been found in its gravitational interaction, as observed in galaxy rotation curves or gravitational lensing effects. The inferred dark matter agglomerations follow almost universal mass density profiles that can be reproduced well in simulations, but have eluded an explanation from a theoretical viewpoint. Forgoing standard (astro-)physical methods, I show that it is possible to derive these profiles from an intriguingly simple mathematical approach that directly determines the most likely spatial configuration of a self-gravitating ensemble of collisionless dark matter particles.

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