Euclid preparation. LIII. LensMC, weak lensing cosmic shear measurement with forward modelling and Markov Chain Monte Carlo sampling
Creators: name: Euclid Collaboration
name: Congedo, G.
name: Miller, L.
name: Taylor, A. N.
name: Cross, N.
name: Duncan, C. A. J.
name: Kitching, T.
name: Martinet, N.
name: Matthew, S.
name: Schrabback, T.
name: Tewes, M.
name: Welikala, N.
name: Aghanim, N.
name: Amara, A.
name: Andreon, S.
name: Auricchio, N.
name: Baldi, M.
name: Bardelli, S.
name: Bender, R.
name: Bodendorf, C.
name: Bonino, D.
name: Branchini, E.
name: Brescia, M.
name: Brinchmann, J.
name: Camera, S.
name: Capobianco, V.
name: Carbone, C.
name: Cardone, V. F.
name: Carretero, J.
name: Casas, S.
name: Castander, F. J.
name: Castellano, M.
name: Cavuoti, S.
name: Cimatti, A.
name: Conselice, C. J.
name: Conversi, L.
name: Copin, Y.
name: Courbin, F.
name: Courtois, H. M.
name: Cropper, M.
name: Da Silva, A.
name: Degaudenzi, H.
name: Di Giorgio, A. M.
name: Dinis, J.
name: Dubath, F.
name: Dupac, X.
name: Farina, M.
name: Farrens, S.
name: Ferriol, S.
name: Fosalba, P.
name: Frailis, M.
name: Franceschi, E.
name: Galeotta, S.
name: Garilli, B.
name: Gillis, B.
name: Giocoli, C.
name: Grazian, A.
name: Grupp, F.
name: Haugan, S. V. H.
name: Holliman, M. S.
name: Holmes, W.
name: Hormuth, F.
name: Hornstrup, A.
name: Hudelot, P.
name: Jahnke, K.
name: Keihänen, E.
name: Kermiche, S.
name: Kiessling, A.
name: Kilbinger, M.
name: Kubik, B.
name: Kuijken, K.
name: Kümmel, M.
name: Kunz, M.
name: Kurki-Suonio, H.
name: Ligori, S.
name: Lilje, P. B.
name: Lindholm, V.
name: Lloro, I.
name: Maino, D.
name: Maiorano, E.
name: Mansutti, O.
name: Marggraf, O.
name: Markovic, K.
name: Marulli, F.
name: Massey, R.
name: Maurogordato, S.
name: McCracken, H. J.
name: Medinaceli, E.
name: Mei, S.
name: Melchior, M.
name: Meneghetti, M.
name: Merlin, E.
name: Meylan, G.
name: Moresco, M.
name: Morin, B.
name: Moscardini, L.
name: Munari, E.
name: Niemi, S. -M.
name: Nightingale, J. W.
name: Padilla, C.
name: Paltani, S.
name: Pasian, F.
name: Pedersen, K.
name: Percival, W. J.
name: Pettorino, V.
name: Pires, S.
name: Polenta, G.
name: Poncet, M.
name: Popa, L. A.
name: Pozzetti, L.
name: Raison, F.
name: Rebolo, R.
name: Renzi, A.
name: Rhodes, J.
name: Riccio, G.
name: Romelli, E.
name: Roncarelli, M.
name: Rossetti, E.
name: Saglia, R.
name: Sapone, D.
name: Sartoris, B.
name: Schneider, P.
name: Secroun, A.
name: Seidel, G.
name: Serrano, S.
name: Sirignano, C.
name: Sirri, G.
name: Stanco, L.
name: Tallada-Crespí, P.
name: Tavagnacco, D.
name: Tereno, I.
name: Toledo-Moreo, R.
name: Torradeflot, F.
name: Tutusaus, I.
name: Valentijn, E. A.
name: Valenziano, L.
name: Vassallo, T.
name: Veropalumbo, A.
name: Wang, Y.
name: Weller, J.
name: Zamorani, G.
name: Zoubian, J.
name: Zucca, E.
name: Biviano, A.
name: Bolzonella, M.
name: Boucaud, A.
name: Bozzo, E.
name: Burigana, C.
name: Colodro-Conde, C.
name: Di Ferdinando, D.
name: Graciá-Carpio, J.
name: Mauri, N.
name: Neissner, C.
name: Nucita, A. A.
name: Sakr, Z.
name: Scottez, V.
name: Tenti, M.
name: Viel, M.
name: Wiesmann, M.
name: Akrami, Y.
name: Allevato, V.
name: Anselmi, S.
name: Baccigalupi, C.
name: Ballardini, M.
name: Borgani, S.
name: Borlaff, A. S.
name: Bruton, S.
name: Cabanac, R.
name: Cappi, A.
name: Carvalho, C. S.
name: Castignani, G.
name: Castro, T.
name: Cañas-Herrera, G.
name: Chambers, K. C.
name: Cooray, A. R.
name: Coupon, J.
name: Davini, S.
name: De Lucia, G.
name: Desprez, G.
name: Di Domizio, S.
name: Dole, H.
name: Díaz-Sánchez, A.
name: Vigo, J. A. Escartin
name: Escoffier, S.
name: Ferrero, I.
name: Finelli, F.
name: Gabarra, L.
name: García-Bellido, J.
name: Gaztanaga, E.
name: Giacomini, F.
name: Gozaliasl, G.
name: Guinet, D.
name: Hall, A.
name: Hildebrandt, H.
name: Ilić, S.
name: Muñoz, A. Jimenez
name: Joudaki, S.
name: Kajava, J. J. E.
name: Kansal, V.
name: Karagiannis, D.
name: Kirkpatrick, C. C.
name: Legrand, L.
name: Macias-Perez, J.
name: Maggio, G.
name: Magliocchetti, M.
name: Maoli, R.
name: Martinelli, M.
name: Martins, C. J. A. P.
name: Maturi, M.
name: Maurin, L.
name: Metcalf, R. B.
name: Migliaccio, M.
name: Monaco, P.
name: Morgante, G.
name: Nadathur, S.
name: Patrizii, L.
name: Peel, A.
name: Pezzotta, A.
name: Popa, V.
name: Porciani, C.
name: Potter, D.
name: Pöntinen, M.
name: Reimberg, P.
name: Rocci, P. -F.
name: Sánchez, A. G.
name: Schewtschenko, J. A.
name: Schneider, A.
name: Sefusatti, E.
name: Sereno, M.
name: Simon, P.
name: Mancini, A. Spurio
name: Stadel, J.
name: Steinwagner, J.
name: Testera, G.
name: Teyssier, R.
name: Toft, S.
name: Tosi, S.
name: Troja, A.
name: Tucci, M.
name: Valieri, C.
name: Valiviita, J.
name: Vergani, D.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: Computation (stat.CO)
subject: FOS: Physical sciences
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences
subject: FOS: Computer and information sciences

description: LensMC is a weak lensing shear measurement method developed for Euclid and Stage-IV surveys. It is based on forward modelling in order to deal with convolution by a point spread function (PSF) with comparable size to many galaxies; sampling the posterior distribution of galaxy parameters via Markov Chain Monte Carlo; and marginalisation over nuisance parameters for each of the 1.5 billion galaxies observed by Euclid. We quantified the scientific performance through high-fidelity images based on the Euclid Flagship simulations and emulation of the Euclid VIS images; realistic clustering with a mean surface number density of 250 arcmin$^{-2}$ ($I_{\rm E}&lt;29.5$) for galaxies, and 6 arcmin$^{-2}$ ($I_{\rm E}&lt;26$) for stars; and a diffraction-limited chromatic PSF with a full width at half maximum of $0.^{\!\prime\prime}2$ and spatial variation across the field of view. LensMC measured objects with a density of 90 arcmin$^{-2}$ ($I_{\rm E}&lt;26.5$) in 4500 deg$^2$. The total shear bias was broken down into measurement (our main focus here) and selection effects (which will be addressed elsewhere). We found measurement multiplicative and additive biases of $m_1=(-3.6\pm0.2)\times10^{-3}$, $m_2=(-4.3\pm0.2)\times10^{-3}$, $c_1=(-1.78\pm0.03)\times10^{-4}$, $c_2=(0.09\pm0.03)\times10^{-4}$; a large detection bias with a multiplicative component of $1.2\times10^{-2}$ and an additive component of $-3\times10^{-4}$; and a measurement PSF leakage of $α_1=(-9\pm3)\times10^{-4}$ and $α_2=(2\pm3)\times10^{-4}$. When model bias is suppressed, the obtained measurement biases are close to Euclid requirement and largely dominated by undetected faint galaxies ($-5\times10^{-3}$). Although significant, model bias will be straightforward to calibrate given the weak sensitivity. LensMC is publicly available at https://gitlab.com/gcongedo/LensMC
description: 28 pages, 18 figures, and 2 tables