Consistent cosmic shear in the face of systematics: a B-mode analysis of KiDS-450, DES-SV and CFHTLenS
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...
| Main Authors: | , , , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
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EDP Sciences
2019
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| _version_ | 1826316120746885120 |
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| author | Asgari, M Heymans, C Hildebrandt, H Miller, L Schneider, P Amon, A Choi, A Erben, T Georgiou, C Harnois-Deraps, J Kuijken, K |
| author_facet | Asgari, M Heymans, C Hildebrandt, H Miller, L Schneider, P Amon, A Choi, A Erben, T Georgiou, C Harnois-Deraps, J Kuijken, K |
| author_sort | Asgari, M |
| collection | OXFORD |
| description | 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. |
| first_indexed | 2024-12-09T03:37:55Z |
| format | Journal article |
| id | oxford-uuid:f11084eb-f14c-40cd-bdb6-9489b0e59d58 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-12-09T03:37:55Z |
| publishDate | 2019 |
| publisher | EDP Sciences |
| record_format | dspace |
| spelling | oxford-uuid:f11084eb-f14c-40cd-bdb6-9489b0e59d582024-12-04T12:15:03ZConsistent cosmic shear in the face of systematics: a B-mode analysis of KiDS-450, DES-SV and CFHTLenSJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:f11084eb-f14c-40cd-bdb6-9489b0e59d58EnglishSymplectic Elements at OxfordEDP Sciences2019Asgari, MHeymans, CHildebrandt, HMiller, LSchneider, PAmon, AChoi, AErben, TGeorgiou, CHarnois-Deraps, JKuijken, KWe 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. |
| spellingShingle | Asgari, M Heymans, C Hildebrandt, H Miller, L Schneider, P Amon, A Choi, A Erben, T Georgiou, C Harnois-Deraps, J Kuijken, K Consistent cosmic shear in the face of systematics: a B-mode analysis of KiDS-450, DES-SV and CFHTLenS |
| title | Consistent cosmic shear in the face of systematics: a B-mode analysis of KiDS-450, DES-SV and CFHTLenS |
| title_full | Consistent cosmic shear in the face of systematics: a B-mode analysis of KiDS-450, DES-SV and CFHTLenS |
| title_fullStr | Consistent cosmic shear in the face of systematics: a B-mode analysis of KiDS-450, DES-SV and CFHTLenS |
| title_full_unstemmed | Consistent cosmic shear in the face of systematics: a B-mode analysis of KiDS-450, DES-SV and CFHTLenS |
| title_short | Consistent cosmic shear in the face of systematics: a B-mode analysis of KiDS-450, DES-SV and CFHTLenS |
| title_sort | consistent cosmic shear in the face of systematics a b mode analysis of kids 450 des sv and cfhtlens |
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