Euclid: The reduced shear approximation and magnification bias for Stage IV cosmic shear experiments
- Creators
- Deshpande, A. C.
- Kitching, T. D.
- Cardone, V. F.
- Taylor, P. L.
- Casas, S.
- Camera, S.
- Carbone, C.
- Kilbinger, M.
- Pettorino, V.
- Sakr, Z.
- Sapone, D.
- Tutusaus, I.
- Auricchio, N.
- Bodendorf, C.
- Bonino, D.
- Brescia, M.
- Capobianco, V.
- Carretero, J.
- Castellano, M.
- Cavuoti, S.
- Cledassou, R.
- Congedo, G.
- Conversi, L.
- Corcione, L.
- Cropper, M.
- Dubath, F.
- Dusini, S.
- Fabbian, G.
- Franceschi, E.
- Fumana, M.
- Garilli, B.
- Grupp, F.
- Hoekstra, H.
- Hormuth, F.
- Israel, H.
- Jahnke, K.
- Kermiche, S.
- Kubik, B.
- Kunz, M.
- Lacasa, F.
- Ligori, S.
- Lilje, P. B.
- Lloro, I.
- Maiorano, E.
- Marggraf, O.
- Massey, R.
- Mei, S.
- Meneghetti, M.
- Meylan, G.
- Moscardini, L.
- Padilla, C.
- Paltani, S.
- Pasian, F.
- Pires, S.
- Polenta, G.
- Poncet, M.
- Raison, F.
- Rhodes, J.
- Roncarelli, M.
- Saglia, R.
- Schneider, P.
- Secroun, A.
- Serrano, S.
- Sirri, G.
- Starck, J. L.
- Sureau, F.
- Taylor, A. N.
- Tereno, I.
- Toledo-Moreo, R.
- Valenziano, L.
- Wang, Y.
- Zoubian, J.
- Euclid Consortium
Abstract
Context. Stage IV weak lensing experiments will offer more than an order of magnitude leap in precision. We must therefore ensure that our analyses remain accurate in this new era. Accordingly, previously ignored systematic effects must be addressed. Aims. In this work, we evaluate the impact of the reduced shear approximation and magnification bias on information obtained from the angular power spectrum. To first-order, the statistics of reduced shear, a combination of shear and convergence, are taken to be equal to those of shear. However, this approximation can induce a bias in the cosmological parameters that can no longer be neglected. A separate bias arises from the statistics of shear being altered by the preferential selection of galaxies and the dilution of their surface densities in high-magnification regions. Methods. The corrections for these systematic effects take similar forms, allowing them to be treated together. We calculated the impact of neglecting these effects on the cosmological parameters that would be determined from Euclid, using cosmic shear tomography. To do so, we employed the Fisher matrix formalism, and included the impact of the super-sample covariance. We also demonstrate how the reduced shear correction can be calculated using a lognormal field forward modelling approach. Results. These effects cause significant biases in Ω_m, σ₈, n_s, Ω_(DE), w₀, and w_a of −0.53σ, 0.43σ, −0.34σ, 1.36σ, −0.68σ, and 1.21σ, respectively. We then show that these lensing biases interact with another systematic effect: the intrinsic alignment of galaxies. Accordingly, we have developed the formalism for an intrinsic alignment-enhanced lensing bias correction. Applying this to Euclid, we find that the additional terms introduced by this correction are sub-dominant.
Additional Information
© 2020 ESO. Article published by EDP Sciences. Received 16 December 2019; Accepted 4 March 2020; Published online 27 April 2020. This paper is published on behalf of the Euclid Consortium. We thank the anonymous referee for their constructive comments, and Paniez Paykari for her programming expertise. ACD and TDK are supported by the Royal Society. PLT acknowledges support for this work from a NASA Postdoctoral Program Fellowship and the UK Science and Technologies Facilities Council. Part of the research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. The Euclid Consortium acknowledges the European Space Agency and the support of a number of agencies and institutes that have supported the development of Euclid, in particular the Academy of Finland, the Agenzia Spaziale Italiana, the Belgian Science Policy, the Canadian Euclid Consortium, the Centre National d'Etudes Spatiales, the Deutsches Zentrum für Luft- und Raumfahrt, the Danish Space Research Institute, the Fundação para a Ciência e a Tecnologia, the Ministerio de Economia y Competitividad, the National Aeronautics and Space Administration, the Netherlandse Onderzoekschool Voor Astronomie, the Norwegian Space Agency, the Romanian Space Agency, the State Secretariat for Education, Research and Innovation (SERI) at the Swiss Space Office (SSO), and the United Kingdom Space Agency. A detailed complete list is available on the Euclid web site (http://www.euclid-ec.org).Attached Files
Published - aa37323-19.pdf
Accepted Version - 1912.07326.pdf
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Additional details
- Alternative title
- Euclid: On the reduced shear approximation and magnification bias for Stage IV cosmic shear experiments
- Eprint ID
- 102798
- Resolver ID
- CaltechAUTHORS:20200427-101700675
- Royal Society
- NASA Postdoctoral Program
- Science and Technologies Facilities Council (STFC)
- NASA/JPL/Caltech
- European Space Agency (ESA)
- Academy of Finland
- Agenzia Spaziale Italiana
- Belgian Federal Science Policy Office (BELSPO)
- Canadian Euclid Consortium
- Centre National de la Recherche Scientifique (CNRS)
- Deutsches Zentrum für Luft- und Raumfahrt (DLR)
- Danish Space Research Institute
- Fundação para a Ciência e a Tecnologia (FCT)
- Ministerio de Economia y ComNetherlanpetitividad (MINECO)
- Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)
- Norwegian Space Agency
- Romanian Space Agency
- State Secretariat for Education, Research and Innovation (SERI)
- Swiss Space Office (SSO)
- United Kingdom Space Agency (UKSA)
- Created
-
2020-04-27Created from EPrint's datestamp field
- Updated
-
2021-11-16Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)