<i>Euclid</i> preparation

We introduce SpectraPyle , a versatile spectral stacking pipeline developed for the Euclid mission’s NISP spectroscopic surveys, aimed at extracting faint emission lines and spectral features from large galaxy samples in the Wide and Deep Surveys. Designed for computational efficiency and flexible configuration, SpectraPyle supports the processing of extensive datasets critical to Euclid ’s non-cosmological science goals. We validated the pipeline using simulated spectra processed to match Euclid ’s expected final data quality. Stacking enables robust recovery of key emission lines, including H α , H β , [O III ], and [N II ], below individual detection limits. However, the measurement of galaxy properties such as star formation rate, dust attenuation, and gas-phase metallicity are biased at stellar mass below log 10 ( M / M ⊙ )∼9 due to the flux-limited nature of Euclid spectroscopic samples, where spectra below the detection threshold lack reliable redshift measurements, preventing effective stacking. The star formation rate–stellar mass relation of the parent sample is recovered reliably only in the deep survey for log 10 ( M / M ⊙ )≳10, whereas the metallicity–mass relation is recovered more accurately over a wider mass range. These limitations are caused by the increased fraction of redshift measurement errors at lower masses and fluxes. We examined the impact of residual redshift contaminants that arises from mis-identified emission lines and noise spikes, on stacked spectra. Even after stringent quality selections, low-level contamination (&lt; 6%) has minimal impact on line fluxes due to the systematically weaker emission of contaminants. A percentile-based analysis of stacked spectra provides a sensitive diagnostic for detecting contamination via coherent spurious features at characteristic wavelengths. While our simulations include most instrumental effects, real Euclid data will require a further refinement of contamination mitigation strategies.

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Publication Details

Journal
Astronomy and Astrophysics
Published
2025-12-18
DOI
https://doi.org/10.1051/0004-6361/202557329
Primary Topic
Galaxies: Formation, Evolution, Phenomena
Type
article
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article

Euclid preparation

M Viel, R. Saglia, M. Brescia, J. Brinchmann et al.
Astronomy and Astrophysics
Galaxies: Formation, Evolution, Phenomena
article

Euclid preparation

M Viel, R. Saglia, M. Brescia, J. Brinchmann, F Passalacqua, M. Ballardini, Lilian Blot, V. Lindholm, P. Tallada-Crespí, S Sacquegna, G. Riccio, M. Castellano, I Tereno, I. Hook, D Sapone, J Brinchmann, M. Brescia, J. García-Bellido, C. Baccigalupi, J. Hjorth, N. Martinet, G. Seidel, F. Dubath, J. Rhodes, J. Carretero, S Bardelli, S. Borgani, S. Di Domizio, M. Sereno, A. Navarro-Alsina, G. Sirri, N. Mauri, C. Giocoli, S. Casas, X. Dupac, K Kiiveri, A. Franco, K. Ganga, A Renzi, A. Troja, P. Tallada-Crespí, F Caro, A. Kiessling, G. Rodighiero, A. Díaz‐Sánchez, Y. Copin, G. Gozaliasl, E. Sellentin, M Radovich, L. Guzzo, T. Contini, F Faustini, Daniele Bertacca, T. Kitching, G Verza, G Castignani, B Sartoris, S. Nadathur, K Jahnke, V. Capobianco, V. Scottez, T. Schrabback, L. Gabarra, M Miluzio, I. A. Zinchenko, Fabio Fontanot, C. J. A. P. Martins, S. Andreon, S. V. H. Haugan, A Enia, S. Dusini, C. Neissner, B. Joachimi, M. Kümmel, G. Leroy, L. Wang, Valérie Gautard, R. Toledo-Moreo, B. Camacho Quevedo, S Bruton, M. Moresco, S. Paltani, F. Raison, G Congedo, B. R. Granett, C. Padilla, Juan José Díaz, A. Da Silva, M. Meneghetti, F Grupp, A. Veropalumbo, D. Maino, L. Valenziano, G. Morgante, K. Ganga, Simon Conseil, H. Hildebrandt, A. Fontana, C. Mancini, S Quai, C. Colodro-Conde, I. Tutusaus, G. Morgante, M. Douspis, M. Hirschmann, I Risso, P Schneider, V. Allevato, G. Mainetti, A. Ealet, J. Väliviita, D. Vibert, J.-L. Starck, W. Gillard, M. Martinelli, D. Karagiannis, S. Escoffier, A. Amara, C. Padilla Aranda, K. George, S. Ferriol, E Keihänen, B. Gillis, Maria Lembo, L. Moscardini, M Sahlén, C. Kirkpatrick, Jenny G. Sorce, E. Medinaceli, A Calabrò, Sandor Kruk, M. Pöntinen, Francesco Shankar, E. Sefusatti, M. Béthermin, M. Farina, S. Camera, F. Mannucci, Ken Paterson, M. Magliocchetti, M Jhabvala, S. Galeotta, A. Venhola, H Kurki-Suonio, M. Archidiacono, R. Farinelli, F Lepori, R. Farinelli, F. Giacomini, E. Bozzo, A. Zacchei, H. Degaudenzi, E. Franceschi, R. Rebolo, H. J. Dickinson, ENRIQUE GAZTAÑAGA, J Martín-Fleitas, T Castro, E. Merlin, P. Monaco, R. Cabanac, Pardis Simon, M. Talia, F. Torradeflot, Y. Mellier, J. Gracia-Carpio, Savvas Nesseris, A. Finoguenov, A Secroun, G. Polenta, K Tanidis, Romain Teyssier, F Hormuth, L. Patrizii, A. Blanchard, F. Finelli⋆, T Gasparetto, M. Melchior, P. Bergamini, T. Vassallo, P.-F Rocci, M. Sereno, S. Pires, D. Potter, M Roncarelli, S. Cavuoti, P Vielzeuf, Emanuele Daddi, E. Romelli, N. Auricchio, E. Rossetti, A. Cappi, D. Vergani, S. J. Liu, Z. Sakr, Shoubaneh Hemmati, K. Pedersen, J. Steinwagner, G. Meylan, Alice Pisani, S. Davini, E Sarpa, Sune Toft, Elisabeta Lusso, Claudia Scarlata, M. Scodeggio, C. Hernández–Monteagudo, S. Paltani, A Pezzotta, O Marggraf, Aurel Schneider, C. Burigana, Vinay Kansal, C. S. Carvalho, M. Siudek, L. Pozzetti, Y. Akrami, S. Kermiche, F. Atrio‐Barandela, Claudio Moretti, L. Bisigello, H. M. Courtois, F. Cogato, D Sciotti, Yun Wang, S. Tosi, A. J. Hall, L. Maurin, Yongtian Kang, G de Lucia, F. Gianotti, G Maggio, S. de la Torre, M. D. Seiffert, F. Finelli, M Kunz, A. Grazian, C. Porciani, S Serrano, S Marcin, D. Di Ferdinando, V. Pettorino, V. Le Brun, J. Macias-Perez, L. Stanco, O Cucciati, G. Zamorani, F. Courbin, M. Viel, P. Hudelot, M. Wiesmann, G. Testera, K Naidoo, Y. Fang, H. Dole, P. Cassata, A Biviano, A. Cimatti, B. Kubik, M. Tucci, M. Bolzonella, Y. Ascasíbar, S Mei, N. Fourmanoit, Z. P. Mao, W. N. Holmes, N. Aghanim, J Lesgourgues, C Valieri, S.-M. Niemi, M Guidi, E Zucca, I. Lloro, S Ligori, A. Mora, L. Leuzzi
article en

Abstract

We introduce SpectraPyle , a versatile spectral stacking pipeline developed for the Euclid mission’s NISP spectroscopic surveys, aimed at extracting faint emission lines and spectral features from large galaxy samples in the Wide and Deep Surveys. Designed for computational efficiency and flexible configuration, SpectraPyle supports the processing of extensive datasets critical to Euclid ’s non-cosmological science goals. We validated the pipeline using simulated spectra processed to match Euclid ’s expected final data quality. Stacking enables robust recovery of key emission lines, including H α , H β , [O III ], and [N II ], below individual detection limits. However, the measurement of galaxy properties such as star formation rate, dust attenuation, and gas-phase metallicity are biased at stellar mass below log 10 ( M / M ⊙ )∼9 due to the flux-limited nature of Euclid spectroscopic samples, where spectra below the detection threshold lack reliable redshift measurements, preventing effective stacking. The star formation rate–stellar mass relation of the parent sample is recovered reliably only in the deep survey for log 10 ( M / M ⊙ )≳10, whereas the metallicity–mass relation is recovered more accurately over a wider mass range. These limitations are caused by the increased fraction of redshift measurement errors at lower masses and fluxes. We examined the impact of residual redshift contaminants that arises from mis-identified emission lines and noise spikes, on stacked spectra. Even after stringent quality selections, low-level contamination (&lt; 6%) has minimal impact on line fluxes due to the systematically weaker emission of contaminants. A percentile-based analysis of stacked spectra provides a sensitive diagnostic for detecting contamination via coherent spurious features at characteristic wavelengths. While our simulations include most instrumental effects, real Euclid data will require a further refinement of contamination mitigation strategies.

Astronomy and AstrophysicsVol. 707
Université Claude Bernard Lyon 1 (FR), Institut polytechnique de Grenoble (FR), University of Geneva (CH), Institució Catalana de Recerca i Estudis Avançats (ES), Leiden University (NL), California Institute of Technology (US), University of Copenhagen (DK), Centre National de la Recherche Scientifique (FR), University of Minnesota (US), Goddard Space Flight Center (US), University of Hawaii System (US), Jet Propulsion Laboratory (US), Université Toulouse III - Paul Sabatier (FR), Consejo Superior de Investigaciones Científicas (ES), University of Bonn (DE), Scuola Internazionale Superiore di Studi Avanzati (IT), University of Padua (IT), University of Lisbon (PT), University of Salento (IT), University of Waterloo (CA), University of Turku (FI), Universidad de La Laguna (ES), Stockholm University (SE), University of Groningen (NL), Université Fédérale de Toulouse Midi-Pyrénées (FR), Lyon College (US), Université Catholique de Lille (FR), Universidade do Porto (PT), Perimeter Institute (CA), University of Oslo (NO), Universidad de Salamanca (ES), Institute for High Energy Physics (ES), University of Milan (IT), Durham University (GB), Universität Innsbruck (AT), University of Saint Joseph (US), Princeton University (US), University of Ferrara (IT), University of Zurich (CH), The Open University (GB), University of California, Irvine (US), Université Paris Cité (FR), Aix-Marseille Université (FR), Heidelberg University (DE), University of Cambridge (GB), Commissariat à l'Énergie Atomique et aux Énergies Alternatives (FR), Université Paris Sciences et Lettres (FR), Université Paris-Saclay (FR), Centre National d'Études Spatiales (FR), Arcetri Astrophysical Observatory (IT), Helsinki Institute of Physics (FI), Astronomical Observatory of Rome (IT), Trieste Astronomical Observatory (IT), Institut d'Astrophysique de Paris (FR), Astronomical Observatory of Capodimonte (IT), European Space Agency (FR), Laboratoire AstroParticule et Cosmologie (FR), Observatoire astronomique de Strasbourg (FR), Brera Astronomical Observatory (IT), University of Surrey (GB), FHNW University of Applied Sciences and Arts Northwestern Switzerland (CH), United Kingdom Space Agency (GB), Universidad Politécnica de Cartagena (ES), Sorbonne Université (FR), University of Oxford (GB), Park University (US), Osservatorio astronomico di Bologna (IT), Astrophysique, Instrumentation et Modélisation (FR), Institute of Astrophysics and Space Sciences (PT), ARC Centre of Excellence for Dark Matter Particle Physics (AU), Sorbonne Paris Cité (FR), Max Planck Institute for Extraterrestrial Physics (DE), Institut d'Estudis Espacials de Catalunya (ES), European Space Astronomy Centre (ES), Istituto Nazionale di Fisica Nucleare, Sezione di Lecce (IT), Istituto Nazionale di Fisica Nucleare, Sezione di Torino (IT), Institute for Space Astrophysics and Planetology (IT), Institut d'Astrophysique Spatiale (FR), Max Planck Institute for Astrophysics (DE), International University of Beirut (LB), Institut Català de Ciències del Clima (ES), Istituto Nazionale di Fisica Nucleare, Sezione di Padova (IT), Osservatorio Astrofisico di Torino (IT), Royal Observatory (GB), Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara (IT), SKA Observatory (GB), Istituto Nazionale di Fisica Nucleare, Sezione di Napoli (IT), Centro de Astrofísica da Universidade do Porto (PT), Max Planck Institute for Astronomy (DE), Institute of Space Sciences (ES), Laboratoire de Physique Théorique (FR), DAWN Center for Independent Living (US), Centre for Theoretical Physics and Astrophysics (UZ), Istituto di Radioastronomia di Bologna (IT), Kavli Institute for the Physics and Mathematics of the Universe (JP), Federico II University Hospital (IT), Unidades Centrales Científico-Técnicas (ES), Mathematical Institute of the Slovak Academy of Sciences (SK), Institute of Astronomy (RU), Collurania Teramo Observatory (IT), Institute of Theoretical Physics (CN), Istituto Nazionale di Fisica Nucleare, Sezione di Genova (IT), Observatoire de la Côte d’Azur (FR), CEA Paris-Saclay (FR), Naples Anesthesia & Physician Associates (US), Instituto de Astrofísica de Canarias (ES), Felix Scholarship (GB), Institut National de Physique Nucléaire et de Physique des Particules (FR), Astronomical Institute of the Slovak Academy of Sciences (SK), Istituto Nazionale di Fisica Nucleare, Sezione di Milano (IT), Institute of Space Science - INFLPR Subsidiary (RO), Computing Center (RU), Centre de Calcul de l’Institut National de Physique Nucléaire et de Physique des Particules (FR), Astronomy and Space (AU), Istituto Nazionale di Fisica Nucleare, Sezione di Bologna (IT), Port d'Informació Científica (ES), Istituto Nazionale di Fisica Nucleare, Sezione di Trieste (IT), Institute for Fundamental Physics of the Universe (IT), Instituto de Física de Cantabria (ES), Flatiron Health (United States) (US), St. Joseph Medical Center (US), Istituto Nazionale di Fisica Nucleare, Sezione di Roma I (IT), Osservatorio Astronomico di Padova (IT), European Space Research Institute (IT), Institut de Recherche sur les Lois Fondamentales de l'Univers (FR), Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (ES), Institut de Recherche en Astrophysique et Planétologie (FR), Infrared Processing and Analysis Center (US), University of Southampton (GB), Osservatorio di Astrofisica e Scienza dello Spazio, Flatiron Institute (US), European Space Research and Technology Centre (NL), University of Florence (IT), University College London (GB), Imperial College London (GB), Space Research Organisation Netherlands (NL), École Polytechnique Fédérale de Lausanne (CH), University of Turin (IT), Swinburne University of Technology (AU), Case Western Reserve University (US), Technical University of Munich (DE), University of Portsmouth (GB), Lancaster University (GB), University of Chile (CL), Heidelberg Institute for Theoretical Studies (DE), École Centrale de Lille (FR), Ludwig-Maximilians-Universität München (DE), University of Genoa (IT), Sapienza University of Rome (IT), University of the Western Cape (ZA), National Institute for Astrophysics (IT), RWTH Aachen University (DE), Université Grenoble Alpes (FR), University of Bologna (IT), Technical University of Denmark (DK), University of Edinburgh (GB), Aalto University (FI)
Openalex Percentile: Top 72%
Galaxies: Formation, Evolution, Phenomena
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