Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Euclid preparation
T2 - XIX. Impact of magnification on photometric galaxy clustering
AU - Euclid Collaboration
AU - Lepori, F.
AU - Tutusaus, I.
AU - Viglione, C.
AU - Bonvin, C.
AU - Camera, S.
AU - Castander, F. J.
AU - Durrer, R.
AU - Fosalba, P.
AU - Jelic-Cizmek, G.
AU - Kunz, M.
AU - Adamek, J.
AU - Casas, S.
AU - Martinelli, M.
AU - Sakr, Z.
AU - Sapone, D.
AU - Amara, A.
AU - Auricchio, N.
AU - Bodendorf, C.
AU - Bonino, D.
AU - Branchini, E.
AU - Brescia, M.
AU - Brinchmann, J.
AU - Capobianco, V.
AU - Carbone, C.
AU - Carretero, J.
AU - Castellano, M.
AU - Cavuoti, S.
AU - Cimatti, A.
AU - Cledassou, R.
AU - Congedo, G.
AU - Conselice, C. J.
AU - Conversi, L.
AU - Copin, Y.
AU - Corcione, L.
AU - Courbin, F.
AU - Silva, A. Da
AU - Degaudenzi, H.
AU - Douspis, M.
AU - Dubath, F.
AU - Dupac, X.
AU - Dusini, S.
AU - Ealet, A.
AU - Farrens, S.
AU - Ferriol, S.
AU - Franceschi, E.
AU - Fumana, M.
AU - Garilli, B.
AU - Gillard, W.
AU - Gillis, B.
AU - Hook, I. M.
N1 - The final, definitive version of this article has been published in the Journal, Astronomy & Astrophysics, 662, A93, 2022, © EDP Sciences.
PY - 2022/6/24
Y1 - 2022/6/24
N2 - We investigate the importance of lensing magnification for estimates of galaxy clustering and its cross-correlation with shear for the photometric sample of Euclid. Using updated specifications, we study the impact of lensing magnification on the constraints and the shift in the estimation of the best fitting cosmological parameters that we expect if this effect is neglected. We follow the prescriptions of the official Euclid Fisher-matrix forecast for the photometric galaxy clustering analysis and the combination of photometric clustering and cosmic shear. The slope of the luminosity function (local count slope), which regulates the amplitude of the lensing magnification, as well as the galaxy bias have been estimated from the Euclid Flagship simulation. We find that magnification significantly affects both the best-fit estimation of cosmological parameters and the constraints in the galaxy clustering analysis of the photometric sample. In particular, including magnification in the analysis reduces the 1$\sigma$ errors on $\Omega_{\text{m},0}, w_{0}, w_a$ at the level of 20-35\%, depending on how well we will be able to independently measure the local count slope. In addition, we find that neglecting magnification in the clustering analysis leads to shifts of up to 1.6$\sigma$ in the best-fit parameters. In the joint analysis of galaxy clustering, cosmic shear and galaxy-galaxy lensing, including magnification does not improve precision but it leads to up to 6$\sigma$ bias if neglected. Therefore, for all models considered in this work, magnification has to be included in the analysis of galaxy clustering and its cross-correlation with the shear signal ($3\times2$pt analysis) for an accurate parameter estimation.
AB - We investigate the importance of lensing magnification for estimates of galaxy clustering and its cross-correlation with shear for the photometric sample of Euclid. Using updated specifications, we study the impact of lensing magnification on the constraints and the shift in the estimation of the best fitting cosmological parameters that we expect if this effect is neglected. We follow the prescriptions of the official Euclid Fisher-matrix forecast for the photometric galaxy clustering analysis and the combination of photometric clustering and cosmic shear. The slope of the luminosity function (local count slope), which regulates the amplitude of the lensing magnification, as well as the galaxy bias have been estimated from the Euclid Flagship simulation. We find that magnification significantly affects both the best-fit estimation of cosmological parameters and the constraints in the galaxy clustering analysis of the photometric sample. In particular, including magnification in the analysis reduces the 1$\sigma$ errors on $\Omega_{\text{m},0}, w_{0}, w_a$ at the level of 20-35\%, depending on how well we will be able to independently measure the local count slope. In addition, we find that neglecting magnification in the clustering analysis leads to shifts of up to 1.6$\sigma$ in the best-fit parameters. In the joint analysis of galaxy clustering, cosmic shear and galaxy-galaxy lensing, including magnification does not improve precision but it leads to up to 6$\sigma$ bias if neglected. Therefore, for all models considered in this work, magnification has to be included in the analysis of galaxy clustering and its cross-correlation with the shear signal ($3\times2$pt analysis) for an accurate parameter estimation.
KW - large-scale structure of Universe
KW - cosmological parameters
KW - cosmology: theory
U2 - 10.1051/0004-6361/202142419
DO - 10.1051/0004-6361/202142419
M3 - Journal article
VL - 662
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
SN - 1432-0746
M1 - A93
ER -