The removal of shear-ellipticity correlations from the cosmic shear signal
نویسندگان
چکیده
منابع مشابه
The removal of shear - ellipticity correlations from the cosmic shear signal via nulling techniques
Aims. To render cosmic shear an astronomical tool of high precision, it is essential to eliminate systematic effects upon its signal, one of the most significant ones being the intrinsic alignment of galaxies. The alignment in tidal fields that are created by the surrounding matter structure induces correlations between the intrinsic ellipticities of source galaxies, as well as correlations bet...
متن کاملThe removal of shear - ellipticity correlations from the cosmic shear signal Influence of photometric redshift errors on the nulling technique
Aims. Cosmic shear, the gravitational lensing on cosmological scales, is regarded one of the most powerful probes to reveal the properties of dark matter and dark energy. To fully utilize its potential, one has to be able to control systematic effects down to below the level of the statistical parameter errors. Particularly worrisome in this respect is the intrinsic alignment of galaxies, causi...
متن کاملQuantifying the Cosmic Web I: The large-scale halo ellipticity-ellipticity and ellipticity-direction correlations
The formation of dark matter halos tends to occur anisotropically along the filaments of the Cosmic Web, which induces both ellipticity-ellipticity (EE) correlations between the shapes of halos, as well as ellipticity-direction (ED) cross-correlations between halo shapes and the directions to neighboring halos. We analyze the halo catalogue and the semi-analytic galaxy catalogue of the recent M...
متن کاملCosmic Shear from Galaxy Spins.
We discuss the origin of galactic angular momentum and the statistics of the present-day spin distribution. It is expected that the galaxy spin axes are correlated with the intermediate principal axis of the gravitational shear tensor. This allows one to reconstruct the shear field and thereby the full gravitational potential from the observed galaxy spin fields. We use the direction of the ang...
متن کاملCosmological Parameters from Cosmic Shear
For a thorough introduction to cosmic shear, see the review of Réfrégier [1] in this volume. Since its first detection in 2000, cosmic shear has proven to be a valuable tool for cosmology. Constraints on cosmological parameters, in particular the (dark+luminous) matter density Ωm and the power spectrum normalization σ8 has been obtained from cosmic shear surveys with observed areas of up to sev...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2009
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361/200912420