Constraints on intrinsic alignment contamination of weak lensing surveys using the MegaZ-LRG sample
نویسندگان
چکیده
منابع مشابه
Intrinsic galaxy shapes and alignments II: Modelling the intrinsic alignment contamination of weak lensing surveys
Intrinsic galaxy alignments constitute the major astrophysical systematic of forthcoming weak gravitational lensing surveys but also yield unique insights into galaxy formation and evolution. We build analytic models for the distribution of galaxy shapes based on halo properties extracted from the Millennium Simulation, differentiating between earlyand late-type galaxies as well as central gala...
متن کاملCosmological Constraints from Weak Lensing Surveys
Focusing on the well motivated aperture mass statistics Map, we study the possibility of constraining cosmological parameters using future space based SNAP class weak lensing missions. Using completely analytical results we construct the covariance matrix for estimators based on two-point and three-point statistics. Our approach incorporates an accurate modelling of higher-order statistics to d...
متن کاملWeak Lensing Surveys and the Intrinsic Correlation of Galaxy Ellipticities
We explore the possibility that an intrinsic correlation between galaxy ellipticities arising during the galaxy formation process may account for part of the shear signal recently reported by several groups engaged in weak gravitational lensing surveys. Using high resolution N-body simulations we measure the projected ellipticities of dark matter halos and their correlations as a function of pa...
متن کاملReducing and constraining the intrinsic galaxy alignment contamination to weak lensing measurements
We present a method for removal of the contaminating effects of intrinsic galaxy alignments, in measurements of cosmic shear from multicolour weak lensing surveys. The method down-weights pairs which are likely to be close in three dimensions, based on spectroscopic or photometric redshifts. Results are dramatic: the intrinsic contamination of the low-redshift Sloan photometric redshift survey ...
متن کاملWeak gravitational lensing: reducing the contamination by intrinsic alignments
Intrinsic alignments of galaxies can mimic to an extent the effects of shear caused by weak gravitational lensing. Previous studies have shown that for shallow surveys with median redshifts zm ∼ 0.1, the intrinsic alignment dominates the lensing signal. For deep surveys with zm ∼ 1, intrinsic alignments are believed to be a significant contaminant of the lensing signal, preventing high-precisio...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2011
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361/201015621