학술논문
Euclid preparation. LensMC, weak lensing cosmic shear measurement with forward modelling and Markov Chain Monte Carlo sampling
Document Type
Working Paper
Author
Euclid Collaboration; Congedo, G.; Miller, L.; Taylor, A. N.; Cross, N.; Duncan, C. A. J.; Kitching, T.; Martinet, N.; Matthew, S.; Schrabback, T.; Tewes, M.; Welikala, N.; Aghanim, N.; Amara, A.; Andreon, S.; Auricchio, N.; Baldi, M.; Bardelli, S.; Bender, R.; Bodendorf, C.; Bonino, D.; Branchini, E.; Brescia, M.; Brinchmann, J.; Camera, S.; Capobianco, V.; Carbone, C.; Cardone, V. F.; Carretero, J.; Casas, S.; Castander, F. J.; Castellano, M.; Cavuoti, S.; Cimatti, A.; Conselice, C. J.; Conversi, L.; Copin, Y.; Courbin, F.; Courtois, H. M.; Cropper, M.; Da Silva, A.; Degaudenzi, H.; Di Giorgio, A. M.; Dinis, J.; Dubath, F.; Dupac, X.; Farina, M.; Farrens, S.; Ferriol, S.; Fosalba, P.; Frailis, M.; Franceschi, E.; Galeotta, S.; Garilli, B.; Gillis, B.; Giocoli, C.; Grazian, A.; Grupp, F.; Haugan, S. V. H.; Holliman, M. S.; Holmes, W.; Hormuth, F.; Hornstrup, A.; Hudelot, P.; Jahnke, K.; Keihänen, E.; Kermiche, S.; Kiessling, A.; Kilbinger, M.; Kubik, B.; Kuijken, K.; Kümmel, M.; Kunz, M.; Kurki-Suonio, H.; Ligori, S.; Lilje, P. B.; Lindholm, V.; Lloro, I.; Maino, D.; Maiorano, E.; Mansutti, O.; Marggraf, O.; Markovic, K.; Marulli, F.; Massey, R.; Maurogordato, S.; McCracken, H. J.; Medinaceli, E.; Mei, S.; Melchior, M.; Meneghetti, M.; Merlin, E.; Meylan, G.; Moresco, M.; Morin, B.; Moscardini, L.; Munari, E.; Niemi, S. -M.; Nightingale, J. W.; Padilla, C.; Paltani, S.; Pasian, F.; Pedersen, K.; Percival, W. J.; Pettorino, V.; Pires, S.; Polenta, G.; Poncet, M.; Popa, L. A.; Pozzetti, L.; Raison, F.; Rebolo, R.; Renzi, A.; Rhodes, J.; Riccio, G.; Romelli, E.; Roncarelli, M.; Rossetti, E.; Saglia, R.; Sapone, D.; Sartoris, B.; Schneider, P.; Secroun, A.; Seidel, G.; Serrano, S.; Sirignano, C.; Sirri, G.; Stanco, L.; Tallada-Crespí, P.; Tavagnacco, D.; Tereno, I.; Toledo-Moreo, R.; Torradeflot, F.; Tutusaus, I.; Valentijn, E. A.; Valenziano, L.; Vassallo, T.; Veropalumbo, A.; Wang, Y.; Weller, J.; Zamorani, G.; Zoubian, J.; Zucca, E.; Biviano, A.; Bolzonella, M.; Boucaud, A.; Bozzo, E.; Burigana, C.; Colodro-Conde, C.; Di Ferdinando, D.; Graciá-Carpio, J.; Mauri, N.; Neissner, C.; Nucita, A. A.; Sakr, Z.; Scottez, V.; Tenti, M.; Viel, M.; Wiesmann, M.; Akrami, Y.; Allevato, V.; Anselmi, S.; Baccigalupi, C.; Ballardini, M.; Borgani, S.; Borlaff, A. S.; Bruton, S.; Cabanac, R.; Cappi, A.; Carvalho, C. S.; Castignani, G.; Castro, T.; Cañas-Herrera, G.; Chambers, K. C.; Cooray, A. R.; Coupon, J.; Davini, S.; De Lucia, G.; Desprez, G.; Di Domizio, S.; Dole, H.; Díaz-Sánchez, A.; Vigo, J. A. Escartin; Escoffier, S.; Ferrero, I.; Finelli, F.; Gabarra, L.; García-Bellido, J.; Gaztanaga, E.; Giacomini, F.; Gozaliasl, G.; Guinet, D.; Hall, A.; Hildebrandt, H.; Ilić, S.; Muñoz, A. Jimenez; Joudaki, S.; Kajava, J. J. E.; Kansal, V.; Karagiannis, D.; Kirkpatrick, C. C.; Legrand, L.; Macias-Perez, J.; Maggio, G.; Magliocchetti, M.; Maoli, R.; Martinelli, M.; Martins, C. J. A. P.; Maturi, M.; Maurin, L.; Metcalf, R. B.; Migliaccio, M.; Monaco, P.; Morgante, G.; Nadathur, S.; Patrizii, L.; Peel, A.; Pezzotta, A.; Popa, V.; Porciani, C.; Potter, D.; Pöntinen, M.; Reimberg, P.; Rocci, P. -F.; Sánchez, A. G.; Schewtschenko, J. A.; Schneider, A.; Sefusatti, E.; Sereno, M.; Simon, P.; Mancini, A. Spurio; Stadel, J.; Steinwagner, J.; Testera, G.; Teyssier, R.; Toft, S.; Tosi, S.; Troja, A.; Tucci, M.; Valieri, C.; Valiviita, J.; Vergani, D.
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Abstract
LensMC is a weak lensing shear measurement method developed for Euclid and Stage-IV surveys. It is based on forward modelling to deal with convolution by a point spread function 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. The scientific performance is quantified 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$^{-2}$ ($I_{\rm E}<29.5$) for galaxies, and 6 arcmin$^{-2}$ ($I_{\rm E}<26$) for stars; and a diffraction-limited chromatic point spread function with a full width at half maximum of $0.^{\!\prime\prime}2$ and spatial variation across the field of view. Objects are measured with a density of 90 arcmin$^{-2}$ ($I_{\rm E}<26.5$) in 4500 deg$^2$. The total shear bias is broken down into measurement (our main focus here) and selection effects (which will be addressed elsewhere). We find: 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 $\alpha_1=(-9\pm3)\times10^{-4}$ and $\alpha_2=(2\pm3)\times10^{-4}$. 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.
Comment: 28 pages, 18 figures, 2 tables
Comment: 28 pages, 18 figures, 2 tables