Article

CFHTLenS tomographic weak lensing cosmological parameter constraints: Mitigating the impact of intrinsic galaxy alignments

Catherine HeymansScottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UKEmma GrocuttScottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UKAlan HeavensImperial Centre for Inference and Cosmology, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ, UKM. KilbingerCEA Saclay, Service d'Astrophysique (SAp), Orme des Merisiers, Bât 709, F-91191 Gif-sur-Yvette, FranceThomas KitchingMullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UKFergus SimpsonScottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UKJonathan BenjaminDepartment of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, CanadaT. ErbenArgelander Institute for Astronomy, University of Bonn, Auf dem Hügel 71, D-53121 Bonn, GermanyH. HildebrandtArgelander Institute for Astronomy, University of Bonn, Auf dem Hügel 71, D-53121 Bonn, GermanyHenk HoekstraDepartment of Physics and Astronomy, University of Victoria, Victoria, BC V8P 5C2, CanadaY. MellierCEA Saclay, Service d'Astrophysique (SAp), Orme des Merisiers, Bât 709, F-91191 Gif-sur-Yvette, FranceL. MillerDepartment of Physics, Oxford University, Keble Road, Oxford OX1 3RH, UKLudovic Van WaerbekeDepartment of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, CanadaMichael L. BrownJodrell Bank Centre for Astrophysics, University of Manchester, Oxford Road, Manchester M13 9PL, UKJean CouponInstitute of Astronomy and Astrophysics, Academia Sinica, PO Box 23-141, Taipei 10617, TaiwanLiping FuKey Lab for Astrophysics, Shanghai Normal University, 100 Guilin Road, 200234 Shanghai, ChinaJoachim Harnois-DérapsCanadian Institute for Theoretical Astrophysics, University of Toronto, Ontario M5S 3H8, CanadaMichael J. HudsonDepartment of Physics and Astronomy, University of Waterloo, Waterloo, ON N2L 3G1, CanadaKonrad KuijkenLeiden Observatory, Leiden University, Niels Bohrweg 2, NL-2333 CA Leiden, the NetherlandsBarnaby RoweDepartment of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UKT. SchrabbackArgelander Institute for Astronomy, University of Bonn, Auf dem Hügel 71, D-53121 Bonn, GermanyE. SemboloniLeiden Observatory, Leiden University, Niels Bohrweg 2, NL-2333 CA Leiden, the NetherlandsSanaz VafaeiDepartment of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, CanadaM. VelanderDepartment of Physics, Oxford University, Keble Road, Oxford OX1 3RH, UK

2013en

ABI

Abstract

We present a finely binned tomographic weak lensing analysis of the Canada–France–Hawaii Telescope Lensing Survey (CFHTLenS) mitigating contamination to the signal from the presence of intrinsic galaxy alignments via the simultaneous fit of a cosmological model and an intrinsic alignment model. CFHTLenS spans 154 square degrees in five optical bands, with accurate shear and photometric redshifts for a galaxy sample with a median redshift of z_m = 0.70. We estimate the 21 sets of cosmic shear correlation functions associated with six redshift bins, each spanning the angular range of 1.5 < θ < 35 arcmin. We combine this CFHTLenS data with auxiliary cosmological probes: the cosmic microwave background with data from WMAP7, baryon acoustic oscillations with data from Baryon Oscillation Spectroscopic Survey and a prior on the Hubble constant from the Hubble Space Telescope distance ladder. This leads to constraints on the normalization of the matter power spectrum σ_8 = 0.799 ± 0.015 and the matter density parameter Ω_m = 0.271 ± 0.010 for a flat Λ cold dark matter (ΛCDM) cosmology. For a flat wCDM cosmology, we constrain the dark energy equation-of-state parameter w = −1.02 ± 0.09. We also provide constraints for curved ΛCDM and wCDM cosmologies. We find the intrinsic alignment contamination to be galaxy-type dependent with a significant intrinsic alignment signal found for early-type galaxies, in contrast to the late-type galaxy sample for which the intrinsic alignment signal is found to be consistent with zero.

Identifiers

DOI: 10.1093/mnras/stt601

Citations and references

Cited by 30 references

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