J-PAS and FLAMINGO: Cosmic voids and void galaxies in the gravitational landscape of photometric surveys
Year: 2026
Type: article
Abstract: Photometric surveys offer a powerful way to map the large-scale structure of the Universe. An essential component of this structure are cosmic voids, but their identification in photometric surveys is complicated by the redshift errors of galaxy tracers. This poses a significant challenge in investigating the environmental effect of cosmic voids on galaxy properties. We provide a two-tier approach to robustly identify and characterise dynamically relevant cosmic voids and their resident galaxies in galaxy mocks of the Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS), assessing whether established trends in void galaxy properties can be detected despite photometric redshift errors. Using FLAMINGO simulation galaxy mocks at z=0.3 and m_i < 20, we compared a FLAMINGO-based ideal ( ) sample to a FLAMINGO-based sample incorporating J-PAS-like photometric redshift errors. We mitigated these errors via a quasi-gravitational potential field computed from the logarithm of the galaxy number density within the two galaxy mocks. We applied a watershed algorithm to a thresholded quasi-potential field, which allowed us to robustly identify dynamically dominant voids within the simulation volume. Subsequently, based on the density field, we defined a sample of massive void galaxies (M_* ≥ 10 FBI JP 10 $ $M_⊙) and a comparison sample of galaxies located in high-density regions. We evaluated our approach by comparing the void population identified in the sample against that from the sample. While photometric errors lead to a slightly lower void abundance and a marginal shift towards larger, less spherical shapes, the overall size and ellipticity distributions show a strong correspondence between the two mocks. The primary impact of photometric uncertainties manifests in the density profiles of the sample voids as a contamination of void interiors with galaxies scattered from the high-density regions. Considering the volume overlap between the individual voids of the two samples, we find that 425 voids out of the 1074 voids detected in the sample have an intersection over union above 0.5. These recovered voids exhibit excellent agreement in their size and shape distributions. Moreover, they collectively occupy approximately 63% of the thresholded quasi-potential volume, which is consistent with their tendency to be larger and more spherical than the general void population. Furthermore, we find that in both galaxy mocks void galaxies tend to have lower stellar masses and bluer colours and that they exhibit enhanced star formation activity compared to galaxies of the same stellar mass in high-density environments. FBI JP JP FBI Our findings suggest that a quasi-gravitational potential may serve as an effective tool for mitigating redshift errors of the order expected for the J-PAS survey. Taking advantage of the quasi-potential smoothing, we have identified and characterised reliable, dynamically dominant underdensities that are less sensitive to small-scale noise. Furthermore, the population of massive void galaxies exhibits expected trends in their properties when compared to galaxies located in higher-density environments.
Source: Astronomy and Astrophysics
Authors: J.A. Mansour, B. McCarthy, L. J. Liivamägi, A. Tamm, R. van de Weygaert, J. Laur, E. Tempel, M. Einasto, P. Heinämäki, J. Schaye, M. Schaller, R. Abramo, A. Hernán-Caballero, V. Marra, J. Alcaniz, N. Benitez, S. Bonoli, S. Carneiro, J. Cenarro, D. Cristóbal-Hornillos, S. Daflon, R. Dupke A. Ederoclite, Rosa M. González Delgado, C. Hernández-Monteagudo, J. Liu, C. López-Sanjuan, A. Marín-Franch, C. M. de Oliveira, M. Moles, F. Roig, L. Sodré Jr, K. Taylor, J. Varela, H. Vázquez Ramió, J. Vilchez, J. Zaragoza-Cardiel
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
Funders: Ministerio de Ciencia, Innovación y Universidades, European Commission, Fundação de Amparo à Pesquisa do Estado de São Paulo, Eesti Teadusagentuur, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Financiadora de Estudos e Projetos, Fundação de Amparo à Pesquisa e Inovação do Espírito Santo, Tartu Ülikool, HORIZON EUROPE Framework Programme
Awards: Galaxies out of nothing - the J-PAS view, G4473005422, Mapping the dark matter of our Galaxy, GAIN4MOST: Galaxy-filament Alignments IN 4MOST, G7011812729, Building excellence in the study of galaxies and cosmology at the University of Tartu, Co-evolution of galaxies and the cosmic web, Radiative and dynamical modeling of engine-powered superluminous supernovae, G8883849568
OpenAlex ID: W7223146289