Schrabback, Tim, Hartlap, Jan, Joachimi, Benjamin, Kilbinger, Martin, Simon, Patrick, Benabed, Karim, ...
We present a tomographic cosmological weak lensing analysis of the HST COSMOS Survey. Applying our lensing-optimized data reduction, principal component interpolation for the ACS PSF, and improved...
Results of the GREAT08 Challenge: An image analysis competition for cosmological lensing (2009)
Bridle, Sarah, Balan, Sreekumar T., Bethge, Matthias, Gentile, Marc, Harmeling, Stefan, Heymans, Catherine, ...
We present the results of the GREAT08 Challenge, a blind analysis challenge to infer weak gravitational lensing shear distortions from images. The primary goal was to stimulate new ideas by...
Semboloni, Elisabetta, Tereno, Ismael, Van Waerbeke, Ludovic, Heymans, Catherine
The current methods available to estimate gravitational shear from astronomical images of galaxies introduce systematic errors which can affect the accuracy of weak lensing cosmological constraints....
Sersiclets - A Matched Filter Generalisation of Shapelets for Weak Lensing Studies (2008)
Ngan, Wai-Hin Wayne, Van Waerbeke, Ludovic, Mahdavi, Andisheh, Heymans, Catherine, Hoekstra, Henk
The precision study of dark matter using weak lensing by large scale structure is strongly constrained by the accuracy with which one can measure galaxy shapes. Several methods have been devised but...
First catalog of strong lens candidates in the COSMOS field (2008)
Faure, Cecile, Kneib, Jean-Paul, Covone, Giovanni, Tasca, Lidia, Leauthaud, Alexie, Capak, Peter, ...
We present the first catalog of 67 strong galaxy-galaxy lens candidates discovered in the 1.64 deg^2 Hubble Space Telescope COSMOS survey. Twenty of these systems display multiple images or strongly...
Semboloni, Elisabetta, Heymans, Catherine, Van Waerbeke, Ludovic, Schneider, Peter
We investigate the impact of the observed correlation between a galaxies shape and its surrounding density field on the measurement of third order weak lensing shear statistics. Using numerical...
First catalog of strong lens candidates in the COSMOS field (2008)
Faure, Cecile, Kneib, Jean-Paul, Covone, Giovanni, Tasca, Lidia, Leauthaud, Alexie, Capak, Peter, ...
We present the first catalog of 67 strong galaxy-galaxy lens candidates discovered in the 1.64 square degree Hubble Space Telescope COSMOS survey. Twenty of these systems display multiple images or...
Handbook for the GREAT08 Challenge: An image analysis competition for cosmological lensing (2008)
Bridle, Sarah, Shawe-Taylor, John, Amara, Adam, Applegate, Douglas, Balan, Sreekumar T., Berge, Joel, ...
The GRavitational lEnsing Accuracy Testing 2008 (GREAT08) Challenge focuses on a problem that is of crucial importance for future observations in cosmology. The shapes of distant galaxies can be used...
Heymans, Catherine, Gray, Meghan E., Peng, Chien Y., Van Waerbeke, Ludovic, Bell, Eric F., Wolf, Christian, ...
We present a high resolution dark matter reconstruction of the z=0.165 Abell 901/902 supercluster from a weak lensing analysis of the HST STAGES survey. We detect the four main structures of the...
First catalog of strong lens candidates in the COSMOS field (2008)
Faure, Cecile, Kneib, Jean-Paul, Covone, Giovanni, Tasca, Lidia, Leauthaud, Alexie, Capak, Peter, ...
Erratum: "First catalog of strong lens candidates in the COSMOS field" (ApJS, 176, 19 [2008]) (2008)
Faure, Cecile, Kneib, Jean-Paul, Covone, Giovanni, Tasca, Lidia, Leauthaud, Alexie, Capak, Peter, ...
Heymans, Catherine, Gray, Meghan E., Peng, Chien Y., Van Waerbeke, Ludovic, Bell, Eric F., Wolf, Christian, ...
We present a high-resolution dark matter reconstruction of the z = 0.165 Abell 901/902 supercluster from a weak lensing analysis of the Hubble Space Telescope STAGES survey. We detect the four main...
First catalog of strong lens candidates in the COSMOS field (2008)
Faure, Cecile, Kneib, Jean-Paul, Covone, Giovanni, Tasca, Lidia, Leauthaud, Alexie, Capak, Peter, ...
We present the first catalog of 67 strong galaxy-galaxy lens candidates discovered in the 1.64 deg2 Hubble Space Telescope COSMOS survey. Twenty of these systems display multiple images or strongly...
The Masses and Shapes of Dark Matter Halos from Galaxy-Galaxy Lensing in the CFHTLS (2007)
Parker, Laura C., Hoekstra, Henk, Hudson, Michael J., Van Waerbeke, Ludovic, Mellier, Yannick
We present the first galaxy-galaxy weak lensing results using early data from the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). These results are based on ~22 sq. deg. of i' data. From this...
Cosmological Constraints From the 100 Square Degree Weak Lensing Survey (2007)
Benjamin, Jonathan, Heymans, Catherine, Semboloni, Elisabetta, Van Waerbeke, Ludovic, Hoekstra, Henk, Erben, Thomas, ...
We present a cosmic shear analysis of the 100 square degree weak lensing survey, combining data from the CFHTLS-Wide, RCS, VIRMOS-DESCART and GaBoDS surveys. Spanning ~100 square degrees, with a...
COSMOS: 3D weak lensing and the growth of structure (2007)
Massey, Richard, Rhodes, Jason, Leauthaud, Alexie, Capak, Peter, Ellis, Richard, Koekemoer, Anton, ...
We present a three dimensional cosmic shear analysis of the Hubble Space Telescope COSMOS survey, the largest ever optical imaging program performed in space. We have measured the shapes of galaxies...
Rhodes, Jason D., Massey, Richard, Albert, Justin, Collins, Nicholas, Ellis, Richard S., Heymans, Catherine, ...
(abridged) We examine the spatial and temporal stability of the HST ACS Wide Field Camera (WFC) point spread function (PSF) using the two square degree COSMOS survey. We show that stochastic aliasing...
Rhodes, Jason D., Massey, Richard, Albert, Justin, Collins, Nicholas, Ellis, Richard S., Heymans, Catherine, ...
(abridged) We examine the spatial and temporal stability of the HST ACS Wide Field Camera (WFC) point spread function (PSF) using the two square degree COSMOS survey. We show that stochastic aliasing...
COSMOS: 3D weak lensing and the growth of structure (2007)
Massey, Richard, Rhodes, Jason, Leauthaud, Alexie, Capak, Peter, Ellis, Richard, Koekemoer, Anton, ...
We present a three dimensional cosmic shear analysis of the Hubble Space Telescope COSMOS survey, the largest ever optical imaging program performed in space. We have measured the shapes of galaxies...
LEMOMAF: Lensed Mock Map Facility (2007)
Forero-Romero, Jaime E., Blaizot, Jérémy, Devriendt, Julien, Van Waerbeke, Ludovic, Guiderdoni, Bruno
LeMoMaF: Lensed Mock Map Facility (2006)
Forero-Romero, Jaime E., Blaizot, Jeremy, Devriendt, Julien, Van Waerbeke, Ludovic, Guiderdoni, Bruno
We present the Lensed Mock Map Facility (LeMoMaF), a tool designed to perform mock weak lensing measurements on numerically simulated chunks of the universe. Coupling N-body simulations to a...
The Shear TEsting Programme 2: Factors affecting high precision weak lensing analyses (2006)
Massey, Richard, Heymans, Catherine, Berge, Joel, Bernstein, Gary, Bridle, Sarah, Clowe, Douglas, ...
The Shear TEsting Programme (STEP) is a collaborative project to improve the accuracy and reliability of weak lensing measurement, in preparation for the next generation of wide-field surveys. We...
Cosmic variance of weak lensing surveys in the non-Gaussian regime (2006)
Semboloni, Elisabetta, Van Waerbeke, Ludovic, Heymans, Catherine, Hamana, Takashi, Colombi, Stephane, White, Martin, ...
The results from weak gravitational lensing analyses are subject to a cosmic variance error term that has previously been estimated assuming Gaussian statistics. In this letter we address the issue...
Heymans, Catherine, White, Martin, Heavens, Alan, Vale, Chris, Van Waerbeke, Ludovic
We investigate the expected correlation between the weak gravitational shear of distant galaxies and the orientation of foreground galaxies, through the use of numerical simulations. This...
Redshift and Shear Calibration: Impact on Cosmic Shear Studies and Survey Design (2006)
Van Waerbeke, Ludovic, White, Martin, Hoekstra, Henk, Heymans, Catherine
The cosmological interpretation of weak lensing by large-scale structures requires knowledge of the redshift distribution of the source galaxies. Current lensing surveys are often calibrated using...
Schimd, Carlo, Tereno, Ismael, Uzan, Jean-Philippe, Mellier, Yannick, Van Waerbeke, Ludovic, Semboloni, Elisabetta, ...
Dark energy can be investigated in two complementary ways, by considering either general parameterizations or physically well-defined models. Following the second route, we explore the constraints on...
The Shear Testing Programme - I. Weak lensing analysis of simulated ground-based observations (2006)
Heymans, Catherine, Van Waerbeke, Ludovic, Bacon, David, Berge, Joel, Bernstein, Gary, Bertin, Emmanuel, ...
The Shear Testing Programme (STEP) is a collaborative project to improve the accuracy and reliability of all weak lensing measurements in preparation for the next generation of wide-field surveys. In...
The Shear TEsting Programme 1: Weak lensing analysis of simulated ground-based observations (2005)
Heymans, Catherine, Van Waerbeke, Ludovic, Bacon, David, Berge, Joel, Bernstein, Gary, Bertin, Emmanuel, ...
The Shear TEsting Programme, STEP, is a collaborative project to improve the accuracy and reliability of all weak lensing measurements in preparation for the next generation of wide-field surveys. In...
Large scale systematic signals in weak lensing surveys (2004)
Vale, Chris, Hoekstra, Henk, Van Waerbeke, Ludovic, White, Martin
We use numerical simulations to model the effect of seeing and extinction modulations on weak lensing surveys. We find that systematic fluctuations in the shear amplitude and source depth can give...
Constraining Dark Energy Evolution with Gravitational Lensing by Large Scale Structures (2003)
Benabed, Karim, Van Waerbeke, Ludovic
We study the sensitivity of weak lensing by large scale structures to the evolution of dark energy. We explore a 2-parameters model of dark energy evolution, inspired by tracking quintessence models....
Pen, Ue-Li, Lu, Tingting, Van Waerbeke, Ludovic, Mellier, Yannick
We present the first optimal power spectrum estimation and three dimensional deprojections for the dark and luminous matter and their cross correlations. The results are obtained using a new optimal...
Detection of dark matter Skewness in the VIRMOS-DESCART survey: Implications for \Omega_0 (2003)
Pen, Ue-Li, Zhang, Tongjie, Van Waerbeke, Ludovic, Mellier, Yannick, Zhang, Pengjie, Dubinski, John
Weak gravitational lensing provides a direct statistical measure of the dark matter distribution. The variance is easiest to measure, which constrains the degenerate product \sigma_8\Omega^0.6. The...
Analysis of two-point statistics of cosmic shear: I. Estimators and covariances (2002)
Schneider, Peter, Van Waerbeke, Ludovic, Kilbinger, Martin, Mellier, Yannick
We derive in this paper expressions for the covariance matrix of the cosmic shear two-point correlation functions which are readily applied to any survey geometry. Furthermore, we consider the more...
Completeness in Weak Lensing Searches for Clusters (2001)
White, Martin, Van Waerbeke, Ludovic, Mackey, Jonathan
Using mock observations of numerical simulations, we investigate the completeness and efficiency of searches for galaxy clusters in weak lensing surveys. While it is possible to search for high mass...
Gravity and Non-gravity Modes in the VIRMOS-DESCART Weak Lensing Survey (2001)
Pen, Ue-Li, Van Waerbeke, Ludovic, Mellier, Yannick
We analyze the weak lensing data of the VIRMOS imaging survey using projections (called E and B-modes) of the two independents observed correlation functions. The E-mode contains all the lensing...
Statistics of Dark Matter Halos from Gravitational Lensing (1999)
Jain, Bhuvnesh, Van Waerbeke, Ludovic
We present a new approach to measure the mass function of dark matter halos and to discriminate models with differing values of Omega through weak gravitational lensing. We measure the distribution...
The evolution rate of quasars at various redshifts (1998)
Hatziminaoglou, Evanthia, Van Waerbeke, Ludovic, Mathez, Guy
The evolution of optically selected quasars is usually supposed to be well described by a single constant parameter, either k_L or k_D, depending whether we refer to luminosity or density evolution....
Scale dependence of the bias investigated by weak lensing (1997)
The statistical analysis of the lensing effects coupled with the statistical analysis of the number counts is a tool to probe directly the relation between the mass and the light. In particular, some...
A new measure for cosmic shear (1997)
Schneider, Peter, Van Waerbeke, Ludovic, Jain, Bhuvnesh, Kruse, Guido
We consider here a new statistical measure for cosmic shear, the aperture mass Map, which is defined as a spatially filtered projected density field and which can be measured directly from the image...