TY - JOUR
T1 - Dark Energy Survey Year 3 results
T2 - magnification modelling and impact on cosmological constraints from galaxy clustering and galaxy-galaxy lensing
AU - DES Collaboration
AU - Elvin-Poole, J.
AU - MacCrann, N.
AU - Everett, S.
AU - Prat, J.
AU - Rykoff, E. S.
AU - De Vicente, J.
AU - Yanny, B.
AU - Herner, K.
AU - Ferté, A.
AU - Di Valentino, E.
AU - Choi, A.
AU - Burke, D. L.
AU - Sevilla-Noarbe, I.
AU - Alarcon, A.
AU - Alves, O.
AU - Amon, A.
AU - Andrade-Oliveira, F.
AU - Baxter, E.
AU - Bechtol, K.
AU - Becker, M. R.
AU - Bernstein, G. M.
AU - Blazek, J.
AU - Camacho, H.
AU - Campos, A.
AU - Carnero Rosell, A.
AU - Carrasco Kind, M.
AU - Cawthon, R.
AU - Chang, C.
AU - Chen, R.
AU - Cordero, J.
AU - Crocce, M.
AU - Davis, C.
AU - Derose, J.
AU - Diehl, H. T.
AU - Dodelson, S.
AU - Doux, C.
AU - Drlica-Wagner, A.
AU - Eckert, K.
AU - Eifler, T. F.
AU - Elsner, F.
AU - Fang, X.
AU - Fosalba, P.
AU - Friedrich, O.
AU - Gatti, M.
AU - Giannini, G.
AU - Gruen, D.
AU - Gruendl, R. A.
AU - Harrison, I.
AU - Hartley, W. G.
AU - Huang, H.
N1 - Publisher Copyright:
© 2023 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.
PY - 2023/8/1
Y1 - 2023/8/1
N2 - We study the effect of magnification in the Dark Energy Survey Year 3 analysis of galaxy clustering and galaxy-galaxy lensing, using two different lens samples: a sample of luminous red galaxies, redMaGiC, and a sample with a redshift-dependent magnitude limit, MagLim. We account for the effect of magnification on both the flux and size selection of galaxies, accounting for systematic effects using the Balrog image simulations. We estimate the impact of magnification on the galaxy clustering and galaxy-galaxy lensing cosmology analysis, finding it to be a significant systematic for the MagLim sample. We show cosmological constraints from the galaxy clustering autocorrelation and galaxy-galaxy lensing signal with different magnifications priors, finding broad consistency in cosmological parameters in ΛCDM and wCDM. However, when magnification bias amplitude is allowed to be free, we find the two-point correlation functions prefer a different amplitude to the fiducial input derived from the image simulations. We validate the magnification analysis by comparing the cross-clustering between lens bins with the prediction from the baseline analysis, which uses only the autocorrelation of the lens bins, indicating that systematics other than magnification may be the cause of the discrepancy. We show that adding the cross-clustering between lens redshift bins to the fit significantly improves the constraints on lens magnification parameters and allows uninformative priors to be used on magnification coefficients, without any loss of constraining power or prior volume concerns.
AB - We study the effect of magnification in the Dark Energy Survey Year 3 analysis of galaxy clustering and galaxy-galaxy lensing, using two different lens samples: a sample of luminous red galaxies, redMaGiC, and a sample with a redshift-dependent magnitude limit, MagLim. We account for the effect of magnification on both the flux and size selection of galaxies, accounting for systematic effects using the Balrog image simulations. We estimate the impact of magnification on the galaxy clustering and galaxy-galaxy lensing cosmology analysis, finding it to be a significant systematic for the MagLim sample. We show cosmological constraints from the galaxy clustering autocorrelation and galaxy-galaxy lensing signal with different magnifications priors, finding broad consistency in cosmological parameters in ΛCDM and wCDM. However, when magnification bias amplitude is allowed to be free, we find the two-point correlation functions prefer a different amplitude to the fiducial input derived from the image simulations. We validate the magnification analysis by comparing the cross-clustering between lens bins with the prediction from the baseline analysis, which uses only the autocorrelation of the lens bins, indicating that systematics other than magnification may be the cause of the discrepancy. We show that adding the cross-clustering between lens redshift bins to the fit significantly improves the constraints on lens magnification parameters and allows uninformative priors to be used on magnification coefficients, without any loss of constraining power or prior volume concerns.
KW - cosmological parameters
KW - cosmology: observations
KW - gravitational lensing: weak
KW - large-scale structure of Universe
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U2 - 10.1093/mnras/stad1594
DO - 10.1093/mnras/stad1594
M3 - Article
AN - SCOPUS:85163855454
SN - 0035-8711
VL - 523
SP - 3649
EP - 3670
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 3
ER -