scholarly journals OzDES multi-object fibre spectroscopy for the Dark Energy Survey: results and second data release

2020 ◽  
Vol 496 (1) ◽  
pp. 19-35 ◽  
Author(s):  
C Lidman ◽  
B E Tucker ◽  
T M Davis ◽  
S A Uddin ◽  
J Asorey ◽  
...  
Keyword(s):  
Dark Energy ◽  
Galactic Nuclei ◽  
Wide Field ◽  
Dark Energy Survey ◽  
Data Release ◽  
History Of ◽  
Survey Results ◽  
Deep Fields ◽  
The Masses ◽  
Energy Survey

ABSTRACT We present a description of the Australian Dark Energy Survey (OzDES) and summarize the results from its 6 years of operations. Using the 2dF fibre positioner and AAOmega spectrograph on the 3.9-m Anglo-Australian Telescope, OzDES has monitored 771 active galactic nuclei, classified hundreds of supernovae, and obtained redshifts for thousands of galaxies that hosted a transient within the 10 deep fields of the Dark Energy Survey. We also present the second OzDES data release, containing the redshifts of almost 30 000 sources, some as faint as rAB = 24 mag, and 375 000 individual spectra. These data, in combination with the time-series photometry from the Dark Energy Survey, will be used to measure the expansion history of the Universe out to z ∼ 1.2 and the masses of hundreds of black holes out to z ∼ 4. OzDES is a template for future surveys that combine simultaneous monitoring of targets with wide-field imaging cameras and wide-field multi-object spectrographs.

scholarly journals Dark Energy Survey Year 1 Results: Wide-field mass maps via forward fitting in harmonic space

2020 ◽  
Vol 493 (4) ◽  
pp. 5662-5679 ◽  
Author(s):  
B Mawdsley ◽  
D Bacon ◽  
C Chang ◽  
P Melchior ◽  
E Rozo ◽  
...  
Keyword(s):  
Dark Energy ◽  
Mapping Technique ◽  
Harmonic Space ◽  
Wide Field ◽  
Direct Inversion ◽  
Dark Energy Survey ◽  
Central Regions ◽  
Fitting In ◽  
Energy Survey ◽  
Good Agreement

ABSTRACT We present new wide-field weak lensing mass maps for the Year 1 Dark Energy Survey (DES) data, generated via a forward fitting approach. This method of producing maps does not impose any prior constraints on the mass distribution to be reconstructed. The technique is found to improve the map reconstruction on the edges of the field compared to the conventional Kaiser–Squires method, which applies a direct inversion on the data; our approach is in good agreement with the previous direct approach in the central regions of the footprint. The mapping technique is assessed and verified with tests on simulations; together with the Kaiser–Squires method, the technique is then applied to data from the DES Year 1 data and the differences between the two methods are compared. We also produce the first DES measurements of the convergence Minkowski functionals and compare them to those measured in simulations.

scholarly journals Wide-Field Lensing Mass Maps from Dark Energy Survey Science Verification Data

2015 ◽  
Vol 115 (5) ◽  
Author(s):  
C. Chang ◽  
V. Vikram ◽  
B. Jain ◽  
D. Bacon ◽  
A. Amara ◽  
...  
Keyword(s):  
Dark Energy ◽  
Wide Field ◽  
Dark Energy Survey ◽  
Energy Survey

scholarly journals OzDES multifibre spectroscopy for the Dark Energy Survey: 3-yr results and first data release

2017 ◽  
Vol 472 (1) ◽  
pp. 273-288 ◽  
Author(s):  
M. J. Childress ◽  
C. Lidman ◽  
T. M. Davis ◽  
B. E. Tucker ◽  
J. Asorey ◽  
...  
Keyword(s):  
Dark Energy ◽  
Dark Energy Survey ◽  
Data Release ◽  
Energy Survey

scholarly journals Dark Energy Survey Year 1 results: validation of weak lensing cluster member contamination estimates from P(z) decomposition

2019 ◽  
Vol 489 (2) ◽  
pp. 2511-2524 ◽  
Author(s):  
T N Varga ◽  
J DeRose ◽  
D Gruen ◽  
T McClintock ◽  
S Seitz ◽  
...  
Keyword(s):  
Dark Energy ◽  
Decomposition Method ◽  
Weak Lensing ◽  
Cluster Member ◽  
Photometric Redshift ◽  
Cluster Mass ◽  
Dark Energy Survey ◽  
Mass Calibration ◽  
The Masses ◽  
Energy Survey

ABSTRACT Weak lensing source galaxy catalogues used in estimating the masses of galaxy clusters can be heavily contaminated by cluster members, prohibiting accurate mass calibration. In this study, we test the performance of an estimator for the extent of cluster member contamination based on decomposing the photometric redshift P(z) of source galaxies into contaminating and background components. We perform a full scale mock analysis on a simulated sky survey approximately mirroring the observational properties of the Dark Energy Survey Year One observations (DES Y1), and find excellent agreement between the true number profile of contaminating cluster member galaxies in the simulation and the estimated one. We further apply the method to estimate the cluster member contamination for the DES Y1 redMaPPer cluster mass calibration analysis, and compare the results to an alternative approach based on the angular correlation of weak lensing source galaxies. We find indications that the correlation based estimates are biased by the selection of the weak lensing sources in the cluster vicinity, which does not strongly impact the P(z) decomposition method. Collectively, these benchmarks demonstrate the strength of the P(z) decomposition method in alleviating membership contamination and enabling highly accurate cluster weak lensing studies without broad exclusion of source galaxies, thereby improving the total constraining power of cluster mass calibration via weak lensing.

scholarly journals The Dark Energy Survey: Data Release 1

2018 ◽  
Vol 239 (2) ◽  
pp. 18 ◽  
Author(s):  
T. M. C. Abbott ◽  
F. B. Abdalla ◽  
S. Allam ◽  
A. Amara ◽  
J. Annis ◽  
...  
Keyword(s):  
Dark Energy ◽  
Survey Data ◽  
Dark Energy Survey ◽  
Data Release ◽  
Energy Survey

scholarly journals Wide-field lensing mass maps from Dark Energy Survey science verification data: Methodology and detailed analysis

2015 ◽  
Vol 92 (2) ◽  
Author(s):  
V. Vikram ◽  
C. Chang ◽  
B. Jain ◽  
D. Bacon ◽  
A. Amara ◽  
...  
Keyword(s):  
Dark Energy ◽  
Detailed Analysis ◽  
Wide Field ◽  
Dark Energy Survey ◽  
Energy Survey

scholarly journals The WiggleZ Dark Energy Survey: final data release and the metallicity of UV-luminous galaxies

2017 ◽  
Vol 474 (3) ◽  
pp. 4151-4168 ◽  
Author(s):  
Michael J Drinkwater ◽  
Zachary J Byrne ◽  
Chris Blake ◽  
Karl Glazebrook ◽  
Sarah Brough ◽  
...  
Keyword(s):  
Dark Energy ◽  
Dark Energy Survey ◽  
Luminous Galaxies ◽  
Data Release ◽  
Final Data ◽  
Energy Survey

scholarly journals Predicting Dark Energy Survey Results Using the Flat Space Cosmology Model

2019 ◽  
Vol 10 (09) ◽  
pp. 1083-1089
Author(s):  
Eugene Terry Tatum​ ◽  
U. V. S. Seshavatharam
Keyword(s):  
Dark Energy ◽  
Flat Space ◽  
Dark Energy Survey ◽  
Survey Results ◽  
Energy Survey

scholarly journals Stellar mass as a galaxy cluster mass proxy: application to the Dark Energy Survey redMaPPer clusters

2020 ◽  
Vol 493 (4) ◽  
pp. 4591-4606 ◽  
Author(s):  
A Palmese ◽  
J Annis ◽  
J Burgad ◽  
A Farahi ◽  
M Soares-Santos ◽  
...  
Keyword(s):  
Dark Energy ◽  
Bayesian Model Averaging ◽  
Galaxy Cluster ◽  
Wide Field ◽  
X Ray ◽  
Mass Scaling ◽  
Cluster Mass ◽  
Dark Energy Survey ◽  
Stellar Masses ◽  
Energy Survey

Abstract We introduce a galaxy cluster mass observable, μ⋆, based on the stellar masses of cluster members, and we present results for the Dark Energy Survey (DES) Year 1 (Y1) observations. Stellar masses are computed using a Bayesian model averaging method, and are validated for DES data using simulations and COSMOS data. We show that μ⋆ works as a promising mass proxy by comparing our predictions to X-ray measurements. We measure the X-ray temperature–μ⋆ relation for a total of 129 clusters matched between the wide-field DES Y1 redMaPPer catalogue and Chandra and XMM archival observations, spanning the redshift range 0.1 < $z$ < 0.7. For a scaling relation that is linear in logarithmic space, we find a slope of α = 0.488 ± 0.043 and a scatter in the X-ray temperature at fixed μ⋆ of $\sigma _{{\rm ln} T_\mathrm{ X}|\mu _\star }= 0.266^{+0.019}_{-0.020}$ for the joint sample. By using the halo mass scaling relations of the X-ray temperature from the Weighing the Giants program, we further derive the μ⋆-conditioned scatter in mass, finding $\sigma _{{\rm ln} M|\mu _\star }= 0.26^{+ 0.15}_{- 0.10}$. These results are competitive with well-established cluster mass proxies used for cosmological analyses, showing that μ⋆ can be used as a reliable and physically motivated mass proxy to derive cosmological constraints.

scholarly journals Quasar lenses in the south: searches over the DES public footprint

2019 ◽  
Vol 489 (2) ◽  
pp. 2525-2535 ◽  
Author(s):  
Adriano Agnello ◽  
Chiara Spiniello
Keyword(s):  
Dark Energy ◽  
Selection Criteria ◽  
High Grade ◽  
X Ray ◽  
Dark Energy Survey ◽  
Public Data ◽  
Data Release ◽  
Energy Survey ◽  
Selection Of

ABSTRACT We have scanned 5000 deg2 of Southern Sky to search for strongly lensed quasars with five methods, all source oriented, but based on different assumptions and selection criteria. We present a list of high-grade candidates from each method (totalling 98 unique, new candidates), to facilitate follow-up spectroscopic campaigns, including two previously unknown quadruplets, WG 210014.9-445206.4 and WG 021416.37-210535.3. We analyse morphological searches based on Gaia multiplet detection and astrometric offsets, fibre-spectroscopic pre-selection, and X-ray and radio pre-selection. The performance and complementarity of the methods are evaluated on a common sample of known lenses in the Dark Energy Survey public Data Release 1 (DR1) footprint. We recovered in total 13 known lenses, of which 8 are quadruplets. Morphological and colour selection of objects, from the WISE andGaia-DR2 surveys, recovers most of those known lenses, but searches in the radio and X-ray cover regimes that are beyond the completeness of Gaia. Given the footprint, pre-selection, and depth limits, the current number of quads indicates that the union of these searches is complete, and the expected purity on high-grade candidates is ${\approx}60{{\ \rm per\ cent}}$. Ongoing, spectroscopic campaigns confirm this estimate.

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