Euclid preparation: X. The Euclid photometric-redshift challenge

G. Desprez; S. Paltani; J. Coupon; I. Almosallam; A. Alvarez-Ayllon; V. Amaro; M. Brescia; M. Brodwin; S. Cavuoti; J. De Vicente-Albendea; S. Fotopoulou; P. W. Hatfield; W. G. Hartley; O. Ilbert; M. J. Jarvis; G. Longo; M. M. Rau; R. Saha; J. S. Speagle; A. Tramacere; M. Castellano; F. Dubath; A. Galametz; M. Kuemmel; C. Laigle; E. Merlin; J. J. Mohr; S. Pilo; M. Salvato; S. Andreon; N. Auricchio; C. Baccigalupi; A. Balaguera-Antolinez; M. Baldi; S. Bardelli; R. Bender; A. Biviano; C. Bodendorf; D. Bonino; E. Bozzo; E. Branchini; J. Brinchmann; C. Burigana; R. Cabanac; S. Camera; V. Capobianco; A. Cappi; C. Carbone; J. Carretero; C. S. Carvalho; R. Casas; S. Casas; F. J. Castander; G. Castignani; A. Cimatti; R. Cledassou; C. Colodro-Conde; G. Congedo; C. J. Conselice; L. Conversi; Y. Copin; L. Corcione; H. M. Courtois; J. -G. Cuby; A. Da Silva; S. de la Torre; H. Degaudenzi; D. Di Ferdinando; M. Douspis; C. A. J. Duncan; X. Dupac; A. Ealet; G. Fabbian; M. Fabricius; S. Farrens; P. G. Ferreira; F. Finelli; P. Fosalba; N. Fourmanoit; M. Frailis; E. Franceschi; M. Fumana; S. Galeotta; B. Garilli; W. Gillard; B. Gillis; C. Giocoli; G. Gozaliasl; J. Gracia-Carpio; F. Grupp; L. Guzzo; M. Hailey; S. V. H. Haugan; W. Holmes; F. Hormuth; A. Humphrey; K. Jahnke; E. Keihanen; S. Kermiche; M. Kilbinger; C. C. Kirkpatrick; T. D. Kitching; R. Kohley; B. Kubik; M. Kunz; H. Kurki-Suonio; S. Ligori; P. B. Lilje; I. Lloro; D. Maino; E. Maiorano; O. Marggraf; K. Markovic; N. Martinet; F. Marulli; R. Massey; M. Maturi; N. Mauri; S. Maurogordato; E. Medinaceli; S. Mei; M. Meneghetti; R. Benton Metcalf; G. Meylan; M. Moresco; L. Moscardini; E. Munari; S. Niemi; C. Padilla; F. Pasian; L. Patrizii; V. Pettorino; S. Pires; G. Polenta; M. Poncet; L. Popa; D. Potter; L. Pozzetti; F. Raison; A. Renzi; J. Rhodes; G. Riccio; E. Rossetti; R. Saglia; D. Sapone; P. Schneider; V. Scottez; A. Secroun; S. Serrano; C. Sirignano; G. Sirri; L. Stanco; D. Stern; F. Sureau; P. Tallada Crespi; D. Tavagnacco; A. N. Taylor; M. Tenti; I. Tereno; R. Toledo-Moreo; F. Torradeflot; L. Valenziano; J. Valiviita; T. Vassallo; M. Viel; Y. Wang; N. Welikala; L. Whittaker; A. Zacchei; G. Zamorani; J. Zoubian; E. Zucca; Euclid Collaboration

doi:10.1051/0004-6361/202039403

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Euclid preparation: X. The Euclid photometric-redshift challenge

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Euclid preparation: X. The Euclid photometric-redshift challenge

G. Desprez, S. Paltani, J. Coupon, I. Almosallam, A. Alvarez-Ayllon, V. Amaro, M. Brescia, M. Brodwin, S. Cavuoti, J. De Vicente-Albendea, …

Astronomy and astrophysics (Berlin), Vol.644, p.A31

01/12/2020

DOI: https://doi.org/10.1051/0004-6361/202039403

Abstract

Astronomy & Astrophysics

Physical Sciences

Science & Technology

Forthcoming large photometric surveys for cosmology require precise and accurate photometric redshift (photo-z) measurements for the success of their main science objectives. However, to date, no method has been able to produce photo-zs at the required accuracy using only the broad-band photometry that those surveys will provide. An assessment of the strengths and weaknesses of current methods is a crucial step in the eventual development of an approach to meet this challenge. We report on the performance of 13 photometric redshift code single value redshift estimates and redshift probability distributions (PDZs) on a common set of data, focusing particularly on the 0.2-2.6 redshift range that the Euclid mission will probe. We designed a challenge using emulated Euclid data drawn from three photometric surveys of the COSMOS field. The data was divided into two samples: one calibration sample for which photometry and redshifts were provided to the participants; and the validation sample, containing only the photometry to ensure a blinded test of the methods. Participants were invited to provide a redshift single value estimate and a PDZ for each source in the validation sample, along with a rejection flag that indicates the sources they consider unfit for use in cosmological analyses. The performance of each method was assessed through a set of informative metrics, using cross-matched spectroscopic and highly-accurate photometric redshifts as the ground truth. We show that the rejection criteria set by participants are efficient in removing strong outliers, that is to say sources for which the photo-z deviates by more than 0.15(1+z) from the spectroscopic-redshift (spec-z). We also show that, while all methods are able to provide reliable single value estimates, several machine-learning methods do not manage to produce useful PDZs. We find that no machine-learning method provides good results in the regions of galaxy color-space that are sparsely populated by spectroscopic-redshifts, for example z> 1. However they generally perform better than template-fitting methods at low redshift (z< 0.7), indicating that template-fitting methods do not use all of the information contained in the photometry. We introduce metrics that quantify both photo-z precision and completeness of the samples (post-rejection), since both contribute to the final figure of merit of the science goals of the survey (e.g., cosmic shear from Euclid). Template-fitting methods provide the best results in these metrics, but we show that a combination of template-fitting results and machine-learning results with rejection criteria can outperform any individual method. On this basis, we argue that further work in identifying how to best select between machine-learning and template-fitting approaches for each individual galaxy should be pursued as a priority.

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Title: Euclid preparation: X. The Euclid photometric-redshift challenge
Creators - without role: G. Desprez - University of Geneva
S. Paltani - University of Geneva
J. Coupon - University of Geneva
I. Almosallam - Saudi Informat Technol Co, Riyadh 12382, Saudi Arabia
A. Alvarez-Ayllon - University of Geneva
V. Amaro - Sun Yat-sen University
M. Brescia - INAF, Osservatorio Astron Capodimonte, Via Moiariello 16, I-80131 Naples, Italy
M. Brodwin - University of Missouri
S. Cavuoti - INAF, Osservatorio Astron Capodimonte, Via Moiariello 16, I-80131 Naples, Italy
J. De Vicente-Albendea - Ctr Invest Energet Medioambient & Tecnol CIEMAT, Avenida Complutense 40, Madrid 28040, Spain
S. Fotopoulou - University of Bristol
P. W. Hatfield - University of Oxford
W. G. Hartley - University of Geneva
O. Ilbert - Aix-Marseille University
M. J. Jarvis - University of Oxford
G. Longo - Univ Federico II, Dept Phys E Pancini, Via Cinthia 6, I-80126 Naples, Italy
M. M. Rau - Carnegie Mellon University
R. Saha - University of Missouri
J. S. Speagle - Ctr Astrophys Harvard & Smithsonian, 60 Garden St, Cambridge, MA 02138 USA
A. Tramacere - University of Geneva
M. Castellano - INAF, Osservatorio Astron Roma, Via Frascati 33, I-00078 Monte Porzio Catone, Italy
F. Dubath - University of Geneva
A. Galametz - University of Geneva
M. Kuemmel - Ludwig Maximilians Univ Munchen, Fak Phys, Univ Sternwarte Munchen, Scheinerstr 1, D-81679 Munich, Germany
C. Laigle - Sorbonne Université
E. Merlin - INAF, Osservatorio Astron Roma, Via Frascati 33, I-00078 Monte Porzio Catone, Italy
J. J. Mohr - Ludwig Maximilians Univ Munchen, Fak Phys, Univ Sternwarte Munchen, Scheinerstr 1, D-81679 Munich, Germany
S. Pilo - INAF, Osservatorio Astron Roma, Via Frascati 33, I-00078 Monte Porzio Catone, Italy
M. Salvato - Max
S. Andreon - INAF, Osservatorio Astron Brera, Via Brera 28, I-20122 Milan, Italy
N. Auricchio - INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy
C. Baccigalupi - Supreme Council Of Health
A. Balaguera-Antolinez - Univ Laguna, 38206 San Cristobal La Laguna, Tenerife, Spain
M. Baldi - INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy
S. Bardelli - INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy
R. Bender - Ludwig Maximilians Univ Munchen, Fak Phys, Univ Sternwarte Munchen, Scheinerstr 1, D-81679 Munich, Germany
A. Biviano - INAF, Osservatorio Astron Trieste, Via GB Tiepolo 11, I-34131 Trieste, Italy
C. Bodendorf - Max
D. Bonino - INAF, Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy
E. Bozzo - University of Geneva
E. Branchini - INAF, Osservatorio Astron Roma, Via Frascati 33, I-00078 Monte Porzio Catone, Italy
J. Brinchmann - Universidade do Porto
C. Burigana - INFN, Sez Bologna, Viale Berti Pichat 6-2, I-40127 Bologna, Italy
R. Cabanac - University of Toulouse
S. Camera - INAF, Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy
V. Capobianco - INAF, Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy
A. Cappi - INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy
C. Carbone - INAF, IASF Milano, Via Alfonso Corti 12, I-20133 Milan, Italy
J. Carretero - Universidade Aberta
C. S. Carvalho - University of Lisbon
R. Casas - S&N
S. Casas - Paris Diderot University
F. J. Castander - S&N
G. Castignani - Ecole Polytech Fed Lausanne, Observ Sauverny, CH-1290 Versoix, Switzerland
A. Cimatti - University of Bologna
R. Cledassou - Ctr Natl Etud Spatiales, Toulouse, France
C. Colodro-Conde - S&N
G. Congedo - University of Edinburgh
C. J. Conselice - University of Nottingham
L. Conversi - European Space Agcy, ESRIN, Largo Galileo Galilei 1, I-00044 Frascati Roma, Italy
Y. Copin - Institut de Physique des 2 Infinis de Lyon
L. Corcione - INAF, Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy
H. M. Courtois - Univ Lyon, UCB Lyon 1, CNRS, IN2P3,IUF,IP2I, Lyon, France
J. -G. Cuby - Aix-Marseille University
A. Da Silva - University of Lisbon
S. de la Torre - Aix-Marseille University
H. Degaudenzi - University of Geneva
D. Di Ferdinando - INFN, Sez Bologna, Viale Berti Pichat 6-2, I-40127 Bologna, Italy
M. Douspis - University of Paris-Saclay
C. A. J. Duncan - University of Oxford
X. Dupac - S&N
A. Ealet - Institut de Physique des 2 Infinis de Lyon
G. Fabbian - University of Sussex
M. Fabricius - Max
S. Farrens - Paris Diderot University
P. G. Ferreira - Imperial Coll London, Blackett Lab, Astrophys Grp, London SW7 2AZ, England
F. Finelli - INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy
P. Fosalba - S&N
N. Fourmanoit - Inst Phys Nucl, 4 Rue Enrico Fermi, F-69622 Villeurbanne, France
M. Frailis - INAF, Osservatorio Astron Trieste, Via GB Tiepolo 11, I-34131 Trieste, Italy
E. Franceschi - INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy
M. Fumana - INAF, IASF Milano, Via Alfonso Corti 12, I-20133 Milan, Italy
S. Galeotta - INAF, Osservatorio Astron Trieste, Via GB Tiepolo 11, I-34131 Trieste, Italy
B. Garilli - INAF, IASF Milano, Via Alfonso Corti 12, I-20133 Milan, Italy
W. Gillard - Aix-Marseille University
B. Gillis - University of Edinburgh
C. Giocoli - INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy
G. Gozaliasl - University of Helsinki
J. Gracia-Carpio - Max
F. Grupp - Max
L. Guzzo - INAF, Osservatorio Astron Brera, Via Brera 28, I-20122 Milan, Italy
M. Hailey - Univ Coll London, Mullard Space Sci Lab, Holmbury St Mary, Dorking RH5 6NT, Surrey, England
S. V. H. Haugan - University of Oslo
W. Holmes - California Institute of Technology
F. Hormuth - von Hoerner & Sulger
A. Humphrey - Universidade do Porto
K. Jahnke - Heidelberg
E. Keihanen - University of Helsinki
S. Kermiche - Aix-Marseille University
M. Kilbinger - Paris Diderot University
C. C. Kirkpatrick - University of Helsinki
T. D. Kitching - Univ Coll London, Mullard Space Sci Lab, Holmbury St Mary, Dorking RH5 6NT, Surrey, England
R. Kohley - S&N
B. Kubik - Univ Lyon, UCB Lyon 1, CNRS, IN2P3,IUF,IP2I, Lyon, France
M. Kunz - University of Geneva
H. Kurki-Suonio - University of Helsinki
S. Ligori - INAF, Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy
P. B. Lilje - University of Oslo
I. Lloro - Nova Southeastern University
D. Maino - INAF, IASF Milano, Via Alfonso Corti 12, I-20133 Milan, Italy
E. Maiorano - INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy
O. Marggraf - University of Bonn
K. Markovic - California Institute of Technology
N. Martinet - Aix-Marseille University
F. Marulli - INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy
R. Massey - Univ Durham, Inst Computat Cosmol, Dept Phys, South Rd, Durham DH1 3LE, England
M. Maturi - Heidelberg Univ, Inst Theoret Phys, Philosophenweg 16, D-69120 Heidelberg, Germany
N. Mauri - University of Bologna
S. Maurogordato - Univ Cote dAzur, CNRS, Lab Lagrange, Observ Cote dAzur, Nice, France
E. Medinaceli - INAF, IASF Bologna, Via Piero Gobetti 101, I-40129 Bologna, Italy
S. Mei - Université Paris Cité
M. Meneghetti - INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy
R. Benton Metcalf - University of Bologna
G. Meylan - Ecole Polytech Fed Lausanne, Observ Sauverny, CH-1290 Versoix, Switzerland
M. Moresco - INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy
L. Moscardini - INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy
E. Munari - INAF, Osservatorio Astron Trieste, Via GB Tiepolo 11, I-34131 Trieste, Italy
S. Niemi - Univ Coll London, Mullard Space Sci Lab, Holmbury St Mary, Dorking RH5 6NT, Surrey, England
C. Padilla - Universidade Aberta
F. Pasian - INAF, Osservatorio Astron Trieste, Via GB Tiepolo 11, I-34131 Trieste, Italy
L. Patrizii - INFN, Sez Bologna, Viale Berti Pichat 6-2, I-40127 Bologna, Italy
V. Pettorino - Paris Diderot University
S. Pires - Paris Diderot University
G. Polenta - Italian Space Agcy, Space Sci Data Ctr, Via Politecn Snc, I-00133 Rome, Italy
M. Poncet - Ctr Natl Etud Spatiales, Toulouse, France
L. Popa - Inst Space Sci, Bucharest 077125, Romania
D. Potter - University of Zurich
L. Pozzetti - INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy
F. Raison - Max
A. Renzi - INFN Padova, Via Marzolo 8, I-35131 Padua, Italy
J. Rhodes - California Institute of Technology
G. Riccio - INAF, Osservatorio Astron Capodimonte, Via Moiariello 16, I-80131 Naples, Italy
E. Rossetti - University of Bologna
R. Saglia - Ludwig Maximilians Univ Munchen, Fak Phys, Univ Sternwarte Munchen, Scheinerstr 1, D-81679 Munich, Germany
D. Sapone - University of Chile
P. Schneider - University of Bonn
V. Scottez - Inst Astrophys Paris, 98Bis Blvd Arago, F-75014 Paris, France
A. Secroun - Aix-Marseille University
S. Serrano - S&N
C. Sirignano - INFN Padova, Via Marzolo 8, I-35131 Padua, Italy
G. Sirri - INFN, Sez Bologna, Viale Berti Pichat 6-2, I-40127 Bologna, Italy
L. Stanco - INFN Padova, Via Marzolo 8, I-35131 Padua, Italy
D. Stern - California Institute of Technology
F. Sureau - Paris Diderot University
P. Tallada Crespi - Ctr Invest Energet Medioambient & Tecnol CIEMAT, Avenida Complutense 40, Madrid 28040, Spain
D. Tavagnacco - INAF, Osservatorio Astron Trieste, Via GB Tiepolo 11, I-34131 Trieste, Italy
A. N. Taylor - University of Edinburgh
M. Tenti - INFN Sezione di Bologna
I. Tereno - University of Lisbon
R. Toledo-Moreo - Univ Politecn Cartagena, Dept Elect & Tecnol Computadoras, Cartagena 30202, Spain
F. Torradeflot - Ctr Invest Energet Medioambient & Tecnol CIEMAT, Avenida Complutense 40, Madrid 28040, Spain
L. Valenziano - INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy
J. Valiviita - University of Helsinki
T. Vassallo - Ludwig Maximilians Univ Munchen, Fak Phys, Univ Sternwarte Munchen, Scheinerstr 1, D-81679 Munich, Germany
M. Viel - Supreme Council Of Health
Y. Wang - California Institute of Technology
N. Welikala - University of Edinburgh
L. Whittaker - University of Manchester
A. Zacchei - INAF, Osservatorio Astron Trieste, Via GB Tiepolo 11, I-34131 Trieste, Italy
G. Zamorani - INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy
J. Zoubian - Aix-Marseille University
E. Zucca - INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy
Euclid Collaboration
Publication Details: Astronomy and astrophysics (Berlin), Vol.644, p.A31
Publisher: Edp Sciences S A
Number of pages: 24
Grant note: Romanian Space Agency Canadian Euclid Consortium Agenzia Spaziale Italiana; Agenzia Spaziale Italiana (ASI) Ministerio de Economia y Competitividad; Spanish Government Fundacao para a Ciencia e a Tecnologia; Fundacao para a Ciencia e a Tecnologia (FCT) National Aeronautics and Space Administration; National Aeronautics & Space Administration (NASA) Norwegian Space Agency Belgian Science Policy; Belgian Federal Science Policy Office United Kingdom Space Agency State Secretariat for Education, Research and Innovation (SERI) at the Swiss Space O ffice (SSO) European Space Agency; European Commission Ts 17/2-1 / German Deutsche Forschungsgemeinschaft, DFG; German Research Foundation (DFG) Netherlandse Onderzoekschool Voor Astronomie 2018-23-HH.0; 1.05.01.88.04 / ASI/INAF; Istituto Nazionale Astrofisica (INAF); Agenzia Spaziale Italiana (ASI) Centre National d'Etudes Spatiales; Centre National D'etudes Spatiales Sinergia program of the Swiss National Science Foundation; Swiss National Science Foundation (SNSF) Danish Space Research Institute
Identifiers: 9918883908331
Academic Unit: King Abdulaziz City for Science & Technology
Language: English
Resource Type: Journal article