scholarly journals KiDS+VIKING-450 and DES-Y1 combined: Cosmology with cosmic shear

2020 ◽  
Vol 638 ◽  
pp. L1 ◽  
Author(s):  
S. Joudaki ◽  
H. Hildebrandt ◽  
D. Traykova ◽  
N. E. Chisari ◽  
C. Heymans ◽  
...  
Keyword(s):  
Dark Energy ◽  
Cosmic Microwave Background ◽  
Gravitational Lensing ◽  
Error Model ◽  
Calibration Error ◽  
Microwave Background ◽  
Weak Gravitational Lensing ◽  
Dark Energy Survey ◽  
Cosmic Shear ◽  
Energy Survey

We present a combined tomographic weak gravitational lensing analysis of the Kilo Degree Survey (KV450) and the Dark Energy Survey (DES-Y1). We homogenize the analysis of these two public cosmic shear datasets by adopting consistent priors and modeling of nonlinear scales, and determine new redshift distributions for DES-Y1 based on deep public spectroscopic surveys. Adopting these revised redshifts results in a 0.8σ reduction in the DES-inferred value for S​8, which decreases to a 0.5σ reduction when including a systematic redshift calibration error model from mock DES data based on the MICE2 simulation. The combined KV450+DES-Y1 constraint on S8 = 0.762−0.024+0.025 is in tension with the Planck 2018 constraint from the cosmic microwave background at the level of 2.5σ. This result highlights the importance of developing methods to provide accurate redshift calibration for current and future weak-lensing surveys.

scholarly journals KiDS+VIKING-450 and DES-Y1 combined: Mitigating baryon feedback uncertainty with COSEBIs

2020 ◽  
Vol 634 ◽  
pp. A127 ◽  
Author(s):  
Marika Asgari ◽  
Tilman Tröster ◽  
Catherine Heymans ◽  
Hendrik Hildebrandt ◽  
Jan Luca van den Busch ◽  
...  
Keyword(s):  
Dark Energy ◽  
Mode Analysis ◽  
Small Scale ◽  
Microwave Background ◽  
Cosmological Constraints ◽  
Dark Energy Survey ◽  
Matter Power Spectrum ◽  
Λcdm Model ◽  
Cosmic Shear ◽  
Energy Survey

We present cosmological constraints from a joint cosmic shear analysis of the Kilo-Degree Survey (KV450) and the Dark Energy Survey (DES-Y1), which were conducted using Complete Orthogonal Sets of E/B-Integrals (COSEBIs). With COSEBIs, we isolated any B-modes that have a non-cosmic shear origin and demonstrate the robustness of our cosmological E-mode analysis as no significant B-modes were detected. We highlight how COSEBIs are fairly insensitive to the amplitude of the non-linear matter power spectrum at high k-scales, mitigating the uncertain impact of baryon feedback in our analysis. COSEBIs, therefore, allowed us to utilise additional small-scale information, improving the DES-Y1 joint constraints on S8 = σ8(Ωm/0.3)0.5 and Ωm by 20%. By adopting a flat ΛCDM model we find S8 = 0.755−0.021+0.019, which is in 3.2σ tension with the Planck Legacy analysis of the cosmic microwave background.

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.

scholarly journals Inference from the small scales of cosmic shear with current and future Dark Energy Survey data

2016 ◽  
Vol 465 (3) ◽  
pp. 2567-2583 ◽  
Author(s):  
N. MacCrann ◽  
J. Aleksić ◽  
A. Amara ◽  
S. L. Bridle ◽  
C. Bruderer ◽  
...  
Keyword(s):  
Dark Energy ◽  
Survey Data ◽  
Dark Energy Survey ◽  
Small Scales ◽  
Cosmic Shear ◽  
Energy Survey

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 Cosmic shear measurements with Dark Energy Survey Science Verification data

2016 ◽  
Vol 94 (2) ◽  
Author(s):  
M. R. Becker ◽  
M. A. Troxel ◽  
N. MacCrann ◽  
E. Krause ◽  
T. F. Eifler ◽  
...  
Keyword(s):  
Dark Energy ◽  
Dark Energy Survey ◽  
Cosmic Shear ◽  
Energy Survey

scholarly journals Dark Energy Survey Year 3 results: Cosmology from cosmic shear and robustness to modeling uncertainty

2022 ◽  
Vol 105 (2) ◽  
Author(s):  
L. F. Secco ◽  
S. Samuroff ◽  
E. Krause ◽  
B. Jain ◽  
J. Blazek ◽  
...  
Keyword(s):  
Dark Energy ◽  
Modeling Uncertainty ◽  
Dark Energy Survey ◽  
Cosmic Shear ◽  
Energy Survey

scholarly journals Dark Energy Survey Year 3 results: Cosmology from cosmic shear and robustness to data calibration

2022 ◽  
Vol 105 (2) ◽  
Author(s):  
A. Amon ◽  
D. Gruen ◽  
M. A. Troxel ◽  
N. MacCrann ◽  
S. Dodelson ◽  
...  
Keyword(s):  
Dark Energy ◽  
Dark Energy Survey ◽  
Cosmic Shear ◽  
Energy Survey ◽  
Data Calibration

scholarly journals Cosmology from cosmic shear with Dark Energy Survey Science Verification data

2016 ◽  
Vol 94 (2) ◽  
Author(s):  
T. Abbott ◽  
F. B. Abdalla ◽  
S. Allam ◽  
A. Amara ◽  
J. Annis ◽  
...  
Keyword(s):  
Dark Energy ◽  
Dark Energy Survey ◽  
Cosmic Shear ◽  
Energy Survey
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