TY - JOUR
T1 - XXXIV. The effect of linear redshift-space distortions in photometric galaxy clustering and its cross-correlation with cosmic shear
AU - Euclid Collaboration
AU - Tanidis, K.
AU - Cardone, V. F.
AU - Martinelli, M.
AU - Tutusaus, I.
AU - Camera, S.
AU - Aghanim, N.
AU - Amara, A.
AU - Andreon, S.
AU - Auricchio, N.
AU - Baldi, M.
AU - Bardelli, S.
AU - Branchini, E.
AU - Brescia, M.
AU - Brinchmann, J.
AU - Capobianco, V.
AU - Carbone, C.
AU - Carretero, J.
AU - Casas, S.
AU - Castellano, M.
AU - Cavuoti, S.
AU - Cimatti, A.
AU - Cledassou, R.
AU - Congedo, G.
AU - Conversi, L.
AU - Copin, Y.
AU - Corcione, L.
AU - Courbin, F.
AU - Courtois, H. M.
AU - Da Silvay, A.
AU - Degaudenzi, H.
AU - Dinis, J.
AU - Dubath, F.
AU - Dupac, X.
AU - Dusini, S.
AU - Farina, M.
AU - Farrens, S.
AU - Ferriol, S.
AU - Fosalba, P.
AU - Frailis, M.
AU - Franceschi, E.
AU - Fumana, M.
AU - Galeotta, S.
AU - Garilli, B.
AU - Gillard, W.
AU - Gillis, B.
AU - Giocoli, C.
AU - Grazian, A.
AU - Grupp, F.
AU - Guzzo, L.
AU - Teyssier, R.
N1 - Publisher Copyright:
© The Authors 2024.
PY - 2024/3/1
Y1 - 2024/3/1
N2 - Context. The cosmological surveys that are planned for the current decade will provide us with unparalleled observations of the distribution of galaxies on cosmic scales, by means of which we can probe the underlying large-scale structure (LSS) of the Universe. This will allow us to test the concordance cosmological model and its extensions. However, precision pushes us to high levels of accuracy in the theoretical modelling of the LSS observables, so that no biases are introduced into the estimation of the cosmological parameters. In particular, effects such as redshift-space distortions (RSD) can become relevant in the computation of harmonic-space power spectra even for the clustering of the photometrically selected galaxies, as has previously been shown in literature. Aims. In this work, we investigate the contribution of linear RSD, as formulated in the Limber approximation by a previous work, in forecast cosmological analyses with the photometric galaxy sample of the Euclid survey. We aim to assess their impact and to quantify the bias on the measurement of cosmological parameters that would be caused if this effect were neglected. Methods. We performed this task by producing mock power spectra for photometric galaxy clustering and weak lensing, as is expected to be obtained from the Euclid survey. We then used a Markov chain Monte Carlo approach to obtain the posterior distributions of cosmological parameters from these simulated observations. Results. When the linear RSD is neglected, significant biases are caused when galaxy correlations are used alone and when they are combined with cosmic shear in the so-called 3 × 2 pt approach. These biases can be equivalent to as much as 5σ when an underlying ΛCDM cosmology is assumed. When the cosmological model is extended to include the equation-of-state parameters of dark energy, the extension parameters can be shifted by more than 1σ.
AB - Context. The cosmological surveys that are planned for the current decade will provide us with unparalleled observations of the distribution of galaxies on cosmic scales, by means of which we can probe the underlying large-scale structure (LSS) of the Universe. This will allow us to test the concordance cosmological model and its extensions. However, precision pushes us to high levels of accuracy in the theoretical modelling of the LSS observables, so that no biases are introduced into the estimation of the cosmological parameters. In particular, effects such as redshift-space distortions (RSD) can become relevant in the computation of harmonic-space power spectra even for the clustering of the photometrically selected galaxies, as has previously been shown in literature. Aims. In this work, we investigate the contribution of linear RSD, as formulated in the Limber approximation by a previous work, in forecast cosmological analyses with the photometric galaxy sample of the Euclid survey. We aim to assess their impact and to quantify the bias on the measurement of cosmological parameters that would be caused if this effect were neglected. Methods. We performed this task by producing mock power spectra for photometric galaxy clustering and weak lensing, as is expected to be obtained from the Euclid survey. We then used a Markov chain Monte Carlo approach to obtain the posterior distributions of cosmological parameters from these simulated observations. Results. When the linear RSD is neglected, significant biases are caused when galaxy correlations are used alone and when they are combined with cosmic shear in the so-called 3 × 2 pt approach. These biases can be equivalent to as much as 5σ when an underlying ΛCDM cosmology is assumed. When the cosmological model is extended to include the equation-of-state parameters of dark energy, the extension parameters can be shifted by more than 1σ.
KW - cosmological parameters
KW - cosmology: theory
KW - large-scale structure of Universe
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U2 - 10.1051/0004-6361/202347870
DO - 10.1051/0004-6361/202347870
M3 - Article
AN - SCOPUS:85186556736
SN - 0004-6361
VL - 683
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A17
ER -