scholarly journals Stacked lensing estimators and their covariance matrices: excess surface mass density versus lensing shear

2018 ◽  
Vol 478 (4) ◽  
pp. 4277-4292 ◽  
Author(s):  
Masato Shirasaki ◽  
Masahiro Takada
Keyword(s):  
Mass Density ◽  
Covariance Matrices ◽  
Surface Mass ◽  
Excess Surface ◽  
Surface Mass Density

scholarly journals Weak lensing analysis of codex clusters using dark energy camera legacy survey: mass–richness relation

2019 ◽  
Vol 491 (2) ◽  
pp. 1643-1655 ◽  
Author(s):  
Anirut Phriksee ◽  
Eric Jullo ◽  
Marceau Limousin ◽  
HuanYuan Shan ◽  
Alexis Finoguenov ◽  
...  
Keyword(s):  
Mass Density ◽  
Weak Lensing ◽  
Imaging Data ◽  
Dynamical Mass ◽  
Surface Mass ◽  
Cluster Sample ◽  
Excess Surface ◽  
Best Fitting ◽  
Surface Mass Density ◽  
Individual Cluster

ABSTRACT We present the weak-lensing analysis of 279 CODEX clusters using imaging data from 4200 deg2 of the DECam Legacy Survey (DECaLS) Data Release 3. The cluster sample results from a joint selection in X-ray, optical richness in the range 20 ≤ λ < 110, and redshift in the range 0.1 ≤ z ≤ 0.2. We model the cluster mass (M200c) and the richness relation with the expression $\left\langle M_{\rm 200c} | \lambda \right\rangle \propto M_{0} \, (\lambda / 40)^{F_{\lambda }}$. By measuring the CODEX cluster sample as an individual cluster, we obtain the best-fitting values, $M_{0} = 3.24^{+0.29}_{-0.27} \times 10^{14} \text{M}_{\odot }$, and $F_{\lambda } = 1.00 ^{+0.22}_{-0.22}$ for the richness scaling index, consistent with a power-law relation. Moreover, we separate the cluster sample into three richness groups; λ = 20–30, 30–50, and 50–110, and measure the stacked excess surface mass density profile in each group. The results show that both methods are consistent. In addition, we find an excellent agreement between our weak lensing based scaling relation and the relation obtained with dynamical masses estimated from cluster member velocity dispersions measured by the SDSS-IV/SPIDERS team. This suggests that the cluster dynamical equilibrium assumption involved in the dynamical mass estimates is statistically robust for a large sample of clusters.

scholarly journals The SAMI Galaxy Survey: stellar population and structural trends across the Fundamental Plane

2021 ◽  
Author(s):  
Francesco D’Eugenio ◽  
Matthew Colless ◽  
Nicholas Scott ◽  
Arjen van der Wel ◽  
Roger L Davies ◽  
...  
Keyword(s):  
Stellar Population ◽  
Mass Density ◽  
Empirical Relation ◽  
Zero Point ◽  
High Signal ◽  
Fundamental Plane ◽  
Surface Mass ◽  
Integral Field Spectroscopy ◽  
Surface Mass Density ◽  
Photometric Measurements

Abstract We study the Fundamental Plane (FP) for a volume- and luminosity-limited sample of 560 early-type galaxies from the SAMI survey. Using r −band sizes and luminosities from new Multi-Gaussian Expansion (MGE) photometric measurements, and treating luminosity as the dependent variable, the FP has coefficients a = 1.294 ± 0.039, b = 0.912 ± 0.025, and zero-point c = 7.067 ± 0.078. We leverage the high signal-to-noise of SAMI integral field spectroscopy, to determine how structural and stellar-population observables affect the scatter about the FP. The FP residuals correlate most strongly (8σ significance) with luminosity-weighted simple-stellar-population (SSP) age. In contrast, the structural observables surface mass density, rotation-to-dispersion ratio, Sérsic index and projected shape all show little or no significant correlation. We connect the FP residuals to the empirical relation between age (or stellar mass-to-light ratio ϒ⋆ ) and surface mass density, the best predictor of SSP age amongst parameters based on FP observables. We show that the FP residuals (anti-)correlate with the residuals of the relation between surface density and ϒ⋆ . This correlation implies that part of the FP scatter is due to the broad age and ϒ⋆ distribution at any given surface mass density. Using virial mass and ϒ⋆ we construct a simulated FP and compare it to the observed FP. We find that, while the empirical relations between observed stellar population relations and FP observables are responsible for most (75 per cent) of the FP scatter, on their own they do not explain the observed tilt of the FP away from the virial plane.

The surface mass density in the solar neighbourhood using red clumps stars in TGASxRAVE

2017 ◽  
Vol 13 (S334) ◽  
pp. 304-305
Author(s):  
Jorrit H. J. Hagen ◽  
Amina Helmi
Keyword(s):  
Vertical Velocity ◽  
Velocity Dispersion ◽  
Mass Density ◽  
Solar Neighbourhood ◽  
Local Distribution ◽  
Surface Mass ◽  
Preliminary Results ◽  
Combining Data ◽  
Surface Mass Density ◽  
Red Clump

AbstractWe investigate the kinematics of red clump stars in the Solar neighbourhood by combining data from the RAVE survey with the TGAS dataset presented in Gaia DR1. Our goal is to put new constraints on the (local) distribution of mass using the Jeans Equations. Here we show the variation of the vertical velocity dispersion as function of height above the mid-plane for both a thin and a thick disk tracer sample and present preliminary results.

scholarly journals Setting the scene for BUFFALO: a study of the matter distribution in the HFF galaxy cluster MACS J0416.1−2403 and its parallel field

2020 ◽  
Vol 494 (1) ◽  
pp. 349-362
Author(s):  
E J Gonzalez ◽  
M Chalela ◽  
M Jauzac ◽  
D Eckert ◽  
M Schaller ◽  
...  
Keyword(s):  
Mass Distribution ◽  
Mass Density ◽  
Galaxy Cluster ◽  
Field Of View ◽  
Evolutionary Stage ◽  
Matter Distribution ◽  
Surface Mass ◽  
X Ray ◽  
Parallel Field ◽  
Surface Mass Density

ABSTRACT In the context of the Beyond Ultradeep Frontier Fields And Legacy Observations (BUFFALO) survey, we present a new analysis of the merging galaxy cluster MACS J0416.1−2403 (z = 0.397) and its parallel field using Hubble Frontier Fields (HFF) data. We measure the surface mass density from a weak-lensing analysis and characterize the overall matter distribution in both the cluster and parallel fields. The surface mass distribution derived for the parallel field shows clumpy overdensities connected by filament-like structures elongated in the direction of the cluster core. We also characterize the X-ray emission in the parallel field and compare it with the lensing mass distribution. We identify five mass peaks at the &gt;5σ level over the two fields, four of them being in the cluster one. Three of them are located close to galaxy overdensities and one is also close to an excess in the X-ray emission. Nevertheless, two of them have neither optical nor X-ray counterpart and are located close to the edges of the field of view, thus further studies are needed to confirm them as substructures. Finally, we compare our results with the predicted subhalo distribution of one of the Hydrangea/C-EAGLE simulated cluster. Significant differences are obtained suggesting the simulated cluster is at a more advanced evolutionary stage than MACS J0416.1−2403. Our results anticipate the upcoming BUFFALO observations that will link the two HFF fields, extending further the HST coverage.

scholarly journals Satellite galaxies in the Illustris-1 simulation: anisotropic locations around relatively isolated hosts

2019 ◽  
Vol 489 (1) ◽  
pp. 459-469 ◽  
Author(s):  
Tereasa G Brainerd ◽  
Masaya Yamamoto
Keyword(s):  
Dark Matter ◽  
Mass Density ◽  
Stellar Mass ◽  
Stellar Surface ◽  
Surface Mass ◽  
Degree Of Anisotropy ◽  
Surface Mass Density ◽  
The Mean ◽  
Satellite Galaxies ◽  
Stellar Masses

ABSTRACT We investigate the locations of satellite galaxies in the z = 0 redshift slice of the hydrodynamical Illustris-1 simulation. As expected from previous work, the satellites are distributed anisotropically in the plane of the sky, with a preference for being located near the major axes of their hosts. Due to misalignment of mass and light within the hosts, the degree of anisotropy is considerably less when satellite locations are measured with respect to the hosts’ stellar surface mass density than when they are measured with respect to the hosts’ dark matter surface mass density. When measured with respect to the hosts’ dark matter surface mass density, the mean satellite location depends strongly on host stellar mass and luminosity, with the satellites of the faintest, least massive hosts showing the greatest anisotropy. When measured with respect to the hosts’ stellar surface mass density, the mean satellite location is essentially independent of host stellar mass and luminosity. In addition, the satellite locations are largely insensitive to the amount of stellar mass used to define the hosts’ stellar surface mass density, as long as at least 50–70 per cent of the hosts’ total stellar mass is used. The satellite locations are dependent upon the stellar masses of the satellites, with the most massive satellites having the most anisotropic distributions.

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.

The kinematics and surface mass density in the solar neighbourhood using TGASxRAVE

2017 ◽  
Vol 12 (S330) ◽  
pp. 160-163
Author(s):  
Jorrit H. J. Hagen ◽  
Amina Helmi
Keyword(s):  
Velocity Distribution ◽  
Mass Density ◽  
Radial Distance ◽  
Radial Velocities ◽  
Solar Neighbourhood ◽  
Local Distribution ◽  
Surface Mass ◽  
Distance Range ◽  
Data Release ◽  
Surface Mass Density

AbstractWe investigate the kinematics of stars in the Solar neighbourhood by combining radial velocities from the latest data release of the RAVE survey with the Tycho-Gaia Astrometric Solution presented in Gaia Data Release 1. We use moments of the velocity distribution to characterise the kinematics over a radial distance range of 6-10 kpc and up to 1 kpc away from the plane. Our ultimate goal is to use these to put new constraints on the (local) distribution of mass using the Jeans Equations.

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