Cosmic shear measurements with Dark Energy Survey science verification data

We present measurements of weak gravitational lensing cosmic shear two-point statistics using Dark Energy Survey Science Verification data. We demonstrate that our results are robust to the choice of shear measurement pipeline, either ngmix or im3shape, and robust to the choice of two-point statistic, including both real and Fourier-space statistics. Our results pass a suite of null tests including tests for B-mode contamination and direct tests for any dependence of the two-point functions on a set of 16 observing conditions and galaxy properties, such as seeing, airmass, galaxy color, galaxy magnitude, etc. We furthermore use a large suite of simulations to compute the covariance matrix of the cosmic shear measurements and assign statistical significance to our null tests. We find that our covariance matrix is consistent with the halo model prediction, indicating that it has the appropriate level of halo sample variance. We compare the same jackknife procedure applied to the data and the simulations in order to search for additional sources of noise not captured by the simulations. We find no statistically significant extra sources of noise in the data. The overall detection significance with tomography for our highest source density catalog is 9.7 sigma . Cosmological constraints from the measurements in this work are presented in a companion paper [DES et al., Phys. Rev. D 94, 022001 (2016).].

[1]  S. Seitz,et al.  Performance of internal covariance estimators for cosmic shear correlation functions , 2015, 1508.00895.

[2]  C. B. D'Andrea,et al.  Cosmology from cosmic shear with Dark Energy Survey science verification data , 2015, 1507.05552.

[3]  R. J. Brunner,et al.  Galaxy clustering, photometric redshifts and diagnosis of systematics in the DES Science Verification data , 2015, 1507.05360.

[4]  T. Eifler,et al.  The impact of intrinsic alignment on current and future cosmic shear surveys , 2015, 1506.08730.

[5]  Matthew R. Becker,et al.  Fourier Band-Power E/B-mode Estimators for Cosmic Shear , 2014, 1412.3851.

[6]  Edwin Valentijn,et al.  Gravitational lensing analysis of the Kilo-Degree Survey , 2015, 1507.00738.

[7]  H. Hoekstra,et al.  Galaxy Alignments: Observations and Impact on Cosmology , 2015, 1504.05465.

[8]  Martin Kilbinger,et al.  Cosmology with cosmic shear observations: a review , 2014, Reports on progress in physics. Physical Society.

[9]  Saba Sehrish,et al.  CosmoSIS: Modular cosmological parameter estimation , 2014, Astron. Comput..

[10]  Scott Dodelson,et al.  Accounting for baryonic effects in cosmic shear tomography: determining a minimal set of nuisance parameters using PCA , 2014, 1405.7423.

[11]  C. Bonnett.  Using neural networks to estimate redshift distributions. An application to CFHTLenS , 2013, 1312.1287.

[12]  Mustapha Ishak,et al.  The Intrinsic Alignment of Galaxies and its Impact on Weak Gravitational Lensing in an Era of Precision Cosmology , 2014, 1407.6990.

[13]  R. Nichol,et al.  Photometric redshift analysis in the Dark Energy Survey Science Verification data , 2014, 1406.4407.

[14]  E. Sheldon.  An implementation of Bayesian lensing shear measurement , 2014, 1403.7669.

[15]  M. Takada,et al.  Super-Sample Covariance in Simulations , 2014, 1401.0385.

[16]  Tim Eifler,et al.  Combining probes of large-scale structure with COSMOLIKE , 2013, 1302.2401.

[17]  Farhan Feroz,et al.  SkyNet: Neural network training tool for machine learning in astronomy , 2013 .

[18]  Farhan Feroz,et al.  SKYNET: an efficient and robust neural network training tool for machine learning in astronomy , 2013, ArXiv.

[19]  Aaron Roodman,et al.  THE THIRD GRAVITATIONAL LENSING ACCURACY TESTING (GREAT3) CHALLENGE HANDBOOK , 2013, 1308.4982.

[20]  Earl Lawrence,et al.  THE COYOTE UNIVERSE EXTENDED: PRECISION EMULATION OF THE MATTER POWER SPECTRUM , 2013, 1304.7849.

[21]  Scott Dodelson,et al.  The Effect of Covariance Estimator Error on Cosmological Parameter Constraints , 2013, 1304.2593.

[22]  Yannick Mellier,et al.  CFHTLenS tomographic weak lensing cosmological parameter constraints: Mitigating the impact of intrinsic galaxy alignments , 2013, 1303.1808.

[23]  M. Takada,et al.  Power spectrum super-sample covariance , 2013, 1302.6994.

[24]  S. Bridle,et al.  im3shape: a maximum likelihood galaxy shear measurement code for cosmic gravitational lensing , 2013, 1302.0183.

[25]  Yannick Mellier,et al.  CFHTLenS: combined probe cosmological model comparison using 2D weak gravitational lensing , 2012, 1212.3338.

[26]  H. Hoekstra,et al.  Bayesian galaxy shape measurement for weak lensing surveys – III. Application to the Canada–France–Hawaii Telescope Lensing Survey , 2012, 1210.8201.

[27]  M. Becker.  Cosmic shear E/B-mode estimation with binned correlation function data , 2012, 1208.0068.

[28]  Adam G. Riess,et al.  Observational probes of cosmic acceleration , 2012, 1201.2434.

[29]  Tamás Budavári,et al.  Astronomy and Computing , 2013 .

[30]  David W. Hogg,et al.  Replacing Standard Galaxy Profiles with Mixtures of Gaussians , 2012, 1210.6563.

[31]  Stefan Hilbert,et al.  COSMIC SHEAR RESULTS FROM THE DEEP LENS SURVEY. I. JOINT CONSTRAINTS ON ΩM AND σ8 WITH A TWO-DIMENSIONAL ANALYSIS , 2012, 1210.2732.

[32]  Takahiro Nishimichi,et al.  REVISING THE HALOFIT MODEL FOR THE NONLINEAR MATTER POWER SPECTRUM , 2012, 1208.2701.

[33]  J. Mohr,et al.  THE BLANCO COSMOLOGY SURVEY: DATA ACQUISITION, PROCESSING, CALIBRATION, QUALITY DIAGNOSTICS, AND DATA RELEASE , 2012, 1204.1210.

[34]  Adam Amara,et al.  Noise bias in weak lensing shape measurements , 2012, 1203.5050.

[35]  Michael Hirsch,et al.  Measurement and calibration of noise bias in weak lensing galaxy shape estimation , 2012, 1203.5049.

[36]  Jeffrey M. Kubo,et al.  THE SDSS CO-ADD: COSMIC SHEAR MEASUREMENT , 2011, 1111.6622.

[37]  W. Marsden.  I and J , 2012 .

[38]  H. Thomas Diehl,et al.  The Dark Energy Survey Camera (DECam) , 2012 .

[39]  D. Schlegel,et al.  Seeing in the dark – II. Cosmic shear in the Sloan Digital Sky Survey , 2011, 1112.3143.

[40]  Gaël Varoquaux,et al.  Scikit-learn: Machine Learning in Python , 2011, J. Mach. Learn. Res..

[41]  Masanori Sato,et al.  SIMULATIONS OF WIDE-FIELD WEAK-LENSING SURVEYS. II. COVARIANCE MATRIX OF REAL-SPACE CORRELATION FUNCTIONS , 2010, 1009.2558.

[42]  M. Bartelmann.  Gravitational lensing , 2010, 1010.3829.

[43]  P. Schneider,et al.  COSEBIs: Extracting the full E-/B-mode information from cosmic shear correlation functions , 2010, 1002.2136.

[44]  E. Krause,et al.  Weak lensing power spectra for precision cosmology: Multiple-deflection, reduced shear and lensing bias corrections , 2009, 0910.3786.

[45]  Masanori Sato,et al.  SIMULATIONS OF WIDE-FIELD WEAK LENSING SURVEYS. I. BASIC STATISTICS AND NON-GAUSSIAN EFFECTS , 2009, 0906.2237.

[46]  P. A. R. Ade,et al.  MEASUREMENT OF COSMIC MICROWAVE BACKGROUND POLARIZATION POWER SPECTRA FROM TWO YEARS OF BICEP DATA , 2009, 0906.1181.

[47]  C. Baugh,et al.  Statistical analysis of galaxy surveys – I. Robust error estimation for two-point clustering statistics , 2008, 0810.1885.

[48]  P. Schneider,et al.  Ray-tracing through the Millennium Simulation: Born corrections and lens-lens coupling in cosmic shear and galaxy-galaxy lensing , 2008, 0809.5035.

[49]  M. Takada,et al.  The impact of non‐Gaussian errors on weak lensing surveys , 2008, 0810.4170.

[50]  P. Schneider,et al.  Analysis of two-point statistics of cosmic shear III. Covariances of shear measures made easy , 2007, 0708.0387.

[51]  T. Kitching,et al.  Bayesian galaxy shape measurement for weak lensing surveys – I. Methodology and a fast-fitting algorithm , 2007, 0708.2340.

[52]  P. Schneider,et al.  Why your model parameter confidences might be too optimistic - unbiased estimation of the inverse covariance matrix , 2006, astro-ph/0608064.

[53]  P. Schneider,et al.  The ring statistics - how to separate E- and B-modes of cosmic shear correlation functions on a finite interval , 2006, astro-ph/0605084.

[54]  Wendy L. Freedman,et al.  Report of the Dark Energy Task Force , 2006, astro-ph/0609591.

[55]  M. Crocce,et al.  Transients from initial conditions in cosmological simulations , 2006, astro-ph/0606505.

[56]  V. Springel.  The Cosmological simulation code GADGET-2 , 2005, astro-ph/0505010.

[57]  K. Gorski,et al.  HEALPix: A Framework for High-Resolution Discretization and Fast Analysis of Data Distributed on the Sphere , 2004, astro-ph/0409513.

[58]  P. Murdin.  MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY , 2005 .

[59]  M. Langlois,et al.  Society of Photo-Optical Instrumentation Engineers , 2005 .

[60]  B. Jain,et al.  Joint galaxy - lensing observables and the dark energy , 2003, astro-ph/0312395.

[61]  E. Hivon,et al.  Fast estimation of polarization power spectra using correlation functions , 2003, astro-ph/0303414.

[62]  G. Bernstein,et al.  The skewness of the aperture mass statistic , 2003, astro-ph/0307393.

[63]  N. Bissantz,et al.  Monthly Notices of the Royal Astronomical Society , 2003 .

[64]  A. Lewis,et al.  Cosmological parameters from CMB and other data: A Monte Carlo approach , 2002, astro-ph/0205436.

[65]  T. Theuns,et al.  Discriminating Weak Lensing from Intrinsic Spin Correlations Using the Curl-Gradient Decomposition , 2000, astro-ph/0012336.

[66]  A. Cooray,et al.  Power Spectrum Covariance of Weak Gravitational Lensing , 2000, astro-ph/0012087.

[67]  M. White,et al.  Power Spectra Estimation for Weak Lensing , 2000, astro-ph/0010352.

[68]  Cambridge,et al.  Detection of weak gravitational lensing by large-scale structure , 2000, astro-ph/0003008.

[69]  G. Bernstein,et al.  Detection of weak gravitational lensing distortions of distant galaxies by cosmic dark matter at large scales , 2000, Nature.

[70]  P. Schneider,et al.  Detection of correlated galaxy ellipticities on CFHT data: first evidence for gravitational lensing by large-scale structures , 2000, astro-ph/0002500.

[71]  U. Seljak.  Weak Lensing Reconstruction and Power Spectrum Estimation: Minimum Variance Methods , 1997, astro-ph/9711124.

[72]  P. Schneider,et al.  A NEW MEASURE FOR COSMIC SHEAR , 1997, astro-ph/9708143.

[73]  C. Seitz,et al.  Steps towards Nonlinear Cluster Inversion Through Gravitational Distortions. I. Basic Considerations and Circular Clusters , 1994, astro-ph/9407032.

[74]  Nick Kaiser,et al.  Weak gravitational lensing of distant galaxies , 1992 .

[75]  J. A. Crowther.  Reports on Progress in Physics , 1941, Nature.