TY - JOUR
T1 - Consistent cosmic shear in the face of systematics
T2 - A B -mode analysis of KiDS-450, DES-SV and CFHTLenS
AU - Asgari, Marika
AU - Heymans, Catherine
AU - Hildebrandt, Hendrik
AU - Miller, Lance
AU - Schneider, Peter
AU - Amon, Alexandra
AU - Choi, Ami
AU - Erben, Thomas
AU - Georgiou, Christos
AU - Harnois-Deraps, Joachim
AU - Kuijken, Konrad
N1 - Publisher Copyright:
© ESO 2019.
PY - 2019/4/1
Y1 - 2019/4/1
N2 - We analyse three public cosmic shear surveys; the Kilo-Degree Survey (KiDS-450), the Dark Energy Survey (DES-SV) and the Canada France Hawaii Telescope Lensing Survey (CFHTLenS). Adopting the "COSEBIs" statistic to cleanly and completely separate the lensing E-modes from the non-lensing B-modes, we detect B-modes in KiDS-450 and CFHTLenS at the level of ∼2.7σ. For DES-SV we detect B-modes at the level of 2.8σ in a non-tomographic analysis, increasing to a 5.5σB-mode detection in a tomographic analysis. In order to understand the origin of these detected B-modes we measure the B-mode signature of a range of different simulated systematics including PSF leakage, random but correlated PSF modelling errors, camera-based additive shear bias and photometric redshift selection bias. We show that any correlation between photometric-noise and the relative orientation of the galaxy to the point-spread-function leads to an ellipticity selection bias in tomographic analyses. This work therefore introduces a new systematic for future lensing surveys to consider. We find that the B-modes in DES-SV appear similar to a superposition of the B-mode signatures from all of the systematics simulated. The KiDS-450 and CFHTLenS B-mode measurements show features that are consistent with a repeating additive shear bias.
AB - We analyse three public cosmic shear surveys; the Kilo-Degree Survey (KiDS-450), the Dark Energy Survey (DES-SV) and the Canada France Hawaii Telescope Lensing Survey (CFHTLenS). Adopting the "COSEBIs" statistic to cleanly and completely separate the lensing E-modes from the non-lensing B-modes, we detect B-modes in KiDS-450 and CFHTLenS at the level of ∼2.7σ. For DES-SV we detect B-modes at the level of 2.8σ in a non-tomographic analysis, increasing to a 5.5σB-mode detection in a tomographic analysis. In order to understand the origin of these detected B-modes we measure the B-mode signature of a range of different simulated systematics including PSF leakage, random but correlated PSF modelling errors, camera-based additive shear bias and photometric redshift selection bias. We show that any correlation between photometric-noise and the relative orientation of the galaxy to the point-spread-function leads to an ellipticity selection bias in tomographic analyses. This work therefore introduces a new systematic for future lensing surveys to consider. We find that the B-modes in DES-SV appear similar to a superposition of the B-mode signatures from all of the systematics simulated. The KiDS-450 and CFHTLenS B-mode measurements show features that are consistent with a repeating additive shear bias.
KW - Cosmology: observations
KW - Gravitational lensing: weak
KW - Methods: data analysis
KW - Methods: statistical
KW - Surveys
UR - http://www.scopus.com/inward/record.url?scp=85065013342&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85065013342&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/201834379
DO - 10.1051/0004-6361/201834379
M3 - Article
AN - SCOPUS:85065013342
SN - 0004-6361
VL - 624
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A134
ER -