scholarly journals Dark Energy Survey year 1 results: the relationship between mass and light around cosmic voids

2019 ◽  
Vol 490 (3) ◽  
pp. 3573-3587 ◽  
Author(s):  
Y Fang ◽  
N Hamaus ◽  
B Jain ◽  
S Pandey ◽  
G Pollina ◽  
...  
Keyword(s):  
Dark Energy ◽  
Signal To Noise Ratio ◽  
Mass Density ◽  
Photometric Redshifts ◽  
Surface Mass ◽  
Dark Energy Survey ◽  
Galaxy Sample ◽  
Cosmic Voids ◽  
The Impact ◽  
Energy Survey

ABSTRACT What are the mass and galaxy profiles of cosmic voids? In this paper, we use two methods to extract voids in the Dark Energy Survey (DES) Year 1 redMaGiC galaxy sample to address this question. We use either 2D slices in projection, or the 3D distribution of galaxies based on photometric redshifts to identify voids. For the mass profile, we measure the tangential shear profiles of background galaxies to infer the excess surface mass density. The signal-to-noise ratio for our lensing measurement ranges between 10.7 and 14.0 for the two void samples. We infer their 3D density profiles by fitting models based on N-body simulations and find good agreement for void radii in the range 15–85 Mpc. Comparison with their galaxy profiles then allows us to test the relation between mass and light at the 10 per cent level, the most stringent test to date. We find very similar shapes for the two profiles, consistent with a linear relationship between mass and light both within and outside the void radius. We validate our analysis with the help of simulated mock catalogues and estimate the impact of photometric redshift uncertainties on the measurement. Our methodology can be used for cosmological applications, including tests of gravity with voids. This is especially promising when the lensing profiles are combined with spectroscopic measurements of void dynamics via redshift-space distortions.

scholarly journals Dark Energy Survey Year 1 results: the effect of intracluster light on photometric redshifts for weak gravitational lensing

2019 ◽  
Vol 488 (3) ◽  
pp. 4389-4399 ◽  
Author(s):  
D Gruen ◽  
Y Zhang ◽  
A Palmese ◽  
B Yanny ◽  
V Busti ◽  
...  
Keyword(s):  
Dark Energy ◽  
Gravitational Lensing ◽  
Mass Density ◽  
Percent Level ◽  
Critical Surface ◽  
Photometric Redshifts ◽  
Surface Mass ◽  
Dark Energy Survey ◽  
Intracluster Light ◽  
Energy Survey

Abstract We study the effect of diffuse intracluster light on the critical surface mass density estimated from photometric redshifts of lensing source galaxies, and the resulting bias in a weak lensing measurement of galaxy cluster mass. Under conservative assumptions, we find the bias to be negligible for imaging surveys like the Dark Energy Survey with a recommended scale cut of ≥200 kpc distance from cluster centres. For significantly deeper lensing source galaxy catalogues from present and future surveys like the Large Synoptic Survey Telescope program, more conservative scale and source magnitude cuts or a correction of the effect may be necessary to achieve percent level lensing measurement accuracy, especially at the massive end of the cluster population.

scholarly journals Dark Energy Survey Year 1 results: the impact of galaxy neighbours on weak lensing cosmology with im3shape

2017 ◽  
Vol 475 (4) ◽  
pp. 4524-4543 ◽  
Author(s):  
S Samuroff ◽  
S L Bridle ◽  
J Zuntz ◽  
M A Troxel ◽  
D Gruen ◽  
...  
Keyword(s):  
Dark Energy ◽  
Weak Lensing ◽  
Dark Energy Survey ◽  
The Impact ◽  
Energy Survey

scholarly journals Cosmic voids and void lensing in the Dark Energy Survey Science Verification data

2016 ◽  
Vol 465 (1) ◽  
pp. 746-759 ◽  
Author(s):  
C. Sánchez ◽  
J. Clampitt ◽  
A. Kovacs ◽  
B. Jain ◽  
J. García-Bellido ◽  
...  
Keyword(s):  
Dark Energy ◽  
Dark Energy Survey ◽  
Cosmic Voids ◽  
Energy Survey

scholarly journals Ridges in the Dark Energy Survey for cosmic trough identification

2020 ◽  
Vol 500 (1) ◽  
pp. 859-870
Author(s):  
Ben Moews ◽  
Morgan A Schmitz ◽  
Andrew J Lawler ◽  
Joe Zuntz ◽  
Alex I Malz ◽  
...  
Keyword(s):  
Dark Energy ◽  
Large Scale ◽  
Mass Density ◽  
Mean Shift ◽  
Large Scale Structure ◽  
Wasserstein Distance ◽  
Scale Structure ◽  
Weak Lensing ◽  
Dark Energy Survey ◽  
Energy Survey

ABSTRACT Cosmic voids and their corresponding redshift-projected mass densities, known as troughs, play an important role in our attempt to model the large-scale structure of the Universe. Understanding these structures enables us to compare the standard model with alternative cosmologies, constrain the dark energy equation of state, and distinguish between different gravitational theories. In this paper, we extend the subspace-constrained mean shift algorithm, a recently introduced method to estimate density ridges, and apply it to 2D weak lensing mass density maps from the Dark Energy Survey Y1 data release to identify curvilinear filamentary structures. We compare the obtained ridges with previous approaches to extract trough structure in the same data, and apply curvelets as an alternative wavelet-based method to constrain densities. We then invoke the Wasserstein distance between noisy and noiseless simulations to validate the denoising capabilities of our method. Our results demonstrate the viability of ridge estimation as a precursor for denoising weak lensing observables to recover the large-scale structure, paving the way for a more versatile and effective search for troughs.

scholarly journals Dark Energy Survey year 1 results: galaxy sample for BAO measurement

2018 ◽  
Vol 482 (2) ◽  
pp. 2807-2822 ◽  
Author(s):  
M Crocce ◽  
A J Ross ◽  
I Sevilla-Noarbe ◽  
E Gaztanaga ◽  
J Elvin-Poole ◽  
...  
Keyword(s):  
Dark Energy ◽  
Dark Energy Survey ◽  
Galaxy Sample ◽  
Energy Survey

scholarly journals Comparison of the excess mass around CFHTLenS galaxy-pairs to predictions from a semi-analytic model using galaxy-galaxy-galaxy lensing

2019 ◽  
Vol 622 ◽  
pp. A104 ◽  
Author(s):  
P. Simon ◽  
H. Saghiha ◽  
S. Hilbert ◽  
P. Schneider ◽  
C. Boever ◽  
...  
Keyword(s):  
Dark Matter ◽  
Galaxy Formation ◽  
Signal To Noise Ratio ◽  
Mass Density ◽  
Synthetic Data ◽  
Analytic Model ◽  
Surface Mass ◽  
Model Predictions ◽  
The Galaxy ◽  
The Impact

The matter environment of galaxies is connected to the physics of galaxy formation and evolution. In particular, the average matter distribution around galaxy pairs is a strong test for galaxy models. Utilising galaxy-galaxy-galaxy lensing as a direct probe, we map out the distribution of correlated surface mass-density around galaxy pairs in the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS). We have compared, for the first time, these so-called excess mass maps to predictions provided by a recent semi-analytic model, which is implanted within the dark-matter Millennium Simulation. We analysed galaxies with stellar masses between 109 − 1011 M⊙ in two photometric redshift bins, for lens redshifts z ≲ 0.6. The projected separation of the galaxy pairs ranges between 170 − 300 h−1 kpc, thereby focusing on pairs inside groups and clusters. To allow us a better interpretation of the maps, we discuss the impact of chance pairs, that is galaxy pairs that appear close to each other in projection only. We have introduced an alternative correlation map that is less affected by projection effects but has a lower signal-to-noise ratio. Our tests with synthetic data demonstrate that the patterns observed in both types of maps are essentially produced by correlated pairs which are close in redshift (Δz ≲ 5 × 10−3). We also verify the excellent accuracy of the map estimators. In an application to the galaxy samples in the CFHTLenS, we obtain a 3σ − 6σ significant detection of the excess mass and an overall good agreement with the galaxy model predictions. There are, however, a few localised spots in the maps where the observational data disagrees with the model predictions on a ≈3.5σ confidence level. Although we have no strong indications for systematic errors in the maps, this disagreement may be related to the residual B-mode pattern observed in the average of all maps. Alternatively, misaligned galaxy pairs inside dark matter halos or lensing by a misaligned distribution of the intra-cluster gas might also cause the unanticipated bulge in the distribution of the excess mass between lens pairs.

scholarly journals The impact of camera optical alignments on weak lensing measures for the Dark Energy Survey

2013 ◽  
Vol 431 (4) ◽  
pp. 3291-3300 ◽  
Author(s):  
Michelle L. Antonik ◽  
David J. Bacon ◽  
Sarah Bridle ◽  
Peter Doel ◽  
David Brooks ◽  
...  
Keyword(s):  
Dark Energy ◽  
Weak Lensing ◽  
Dark Energy Survey ◽  
The Impact ◽  
Energy Survey

scholarly journals Dark energy survey year 3 results: Covariance modelling and its impact on parameter estimation and quality of fit

2021 ◽  
Author(s):  
O Friedrich ◽  
F Andrade-Oliveira ◽  
H Camacho ◽  
O Alves ◽  
R Rosenfeld ◽  
...  
Keyword(s):  
Parameter Estimation ◽  
Dark Energy ◽  
Goodness Of Fit ◽  
Function Analysis ◽  
State Parameter ◽  
Covariance Model ◽  
Dark Energy Survey ◽  
The Impact ◽  
Energy Survey

Abstract We describe and test the fiducial covariance matrix model for the combined 2-point function analysis of the Dark Energy Survey Year 3 (DES-Y3) dataset. Using a variety of new ansatzes for covariance modelling and testing we validate the assumptions and approximations of this model. These include the assumption of Gaussian likelihood, the trispectrum contribution to the covariance, the impact of evaluating the model at a wrong set of parameters, the impact of masking and survey geometry, deviations from Poissonian shot-noise, galaxy weighting schemes and other, sub-dominant effects. We find that our covariance model is robust and that its approximations have little impact on goodness-of-fit and parameter estimation. The largest impact on best-fit figure-of-merit arises from the so-called fsky approximation for dealing with finite survey area, which on average increases the χ2 between maximum posterior model and measurement by $3.7{{\ \rm per\ cent}}$ (Δχ2 ≈ 18.9). Standard methods to go beyond this approximation fail for DES-Y3, but we derive an approximate scheme to deal with these features. For parameter estimation, our ignorance of the exact parameters at which to evaluate our covariance model causes the dominant effect. We find that it increases the scatter of maximum posterior values for Ωm and σ8 by about $3{{\ \rm per\ cent}}$ and for the dark energy equation of state parameter by about $5{{\ \rm per\ cent}}$.

scholarly journals Dark Energy Survey Year 1 results: the lensing imprint of cosmic voids on the cosmic microwave background

2020 ◽  
Vol 500 (1) ◽  
pp. 464-480
Author(s):  
P Vielzeuf ◽  
A Kovács ◽  
U Demirbozan ◽  
P Fosalba ◽  
E Baxter ◽  
...  
Keyword(s):  
Dark Energy ◽  
Cosmic Microwave Background ◽  
Microwave Background ◽  
Process Yield ◽  
Significance Level ◽  
Dark Energy Survey ◽  
Best Fitting ◽  
Cosmic Voids ◽  
Measurement Strategies ◽  
Energy Survey

ABSTRACT Cosmic voids gravitationally lens the cosmic microwave background (CMB) radiation, resulting in a distinct imprint on degree scales. We use the simulated CMB lensing convergence map from the Marenostrum Institut de Ciencias de l’Espai (MICE) N-body simulation to calibrate our detection strategy for a given void definition and galaxy tracer density. We then identify cosmic voids in Dark Energy Survey (DES) Year 1 data and stack the Planck 2015 lensing convergence map on their locations, probing the consistency of simulated and observed void lensing signals. When fixing the shape of the stacked convergence profile to that calibrated from simulations, we find imprints at the 3σ significance level for various analysis choices. The best measurement strategies based on the MICE calibration process yield S/N ≈ 4 for DES Y1, and the best-fitting amplitude recovered from the data is consistent with expectations from MICE (A ≈ 1). Given these results as well as the agreement between them and N-body simulations, we conclude that the previously reported excess integrated Sachs–Wolfe (ISW) signal associated with cosmic voids in DES Y1 has no counterpart in the Planck CMB lensing map.

Sign in / Sign up

Export Citation Format

Share Document