García Argumánez, ÁngelaPérez González, Pablo GuillermoGil De Paz, Armando2023-06-222023-06-222023-02-010004-637X10.3847/1538-4357/aca8ffhttps://hdl.handle.net/20.500.14352/73356© 2023 The Author(s). Artículo firmado por 23 autores. We sincerely thank the referee for the thorough reading and insightful comments that helped to improve the quality of this work. This research has been funded by grants PGC2018- 093499-B-I00 and RTI2018-096188-B-I00 funded by MCIN/ AEI/10.13039/501100011033. Á.G.A. acknowledges the support of the Universidad Complutense de Madrid through the predoctoral grant CT17/17-CT18/17. A.Y. is supported by an appointment to the NASA Postdoctoral Program (NPP) at NASA Goddard Space Flight Center, administered by Oak Ridge Associated Universities under contract with NASA. L.C. acknowledges financial support from Comunidad de Madrid under Atracción de Talento grant 2018-T2/TIC-11612. R.M. M. acknowledges support from Spanish Ministerio de Ciencia, Innovación y Universidades through grant PGC2018-093499- B-I00, from MDM-2017-0737 Unidad de Excelencia “Maria de Maeztu”-Centro de Astrobiología (INTA-CSIC) by the Spanish Ministry of Science and Innovation/State Agency of Research MCIN/AEI/ 10.13039/501100011033 and by “ERDF A way of making Europe,” and also from the Instituto Nacional de Técnica Aeroespacial SHARDS-JWST project through the PRE-SHARDSJWST/2020 grant.We use the Illustris-1 simulation to explore the capabilities of the Hubble Space Telescope (HST) and James Webb Space Telescope (JWST) data to analyze the stellar populations in high-redshift galaxies, taking advantage of the combined depth, spatial resolution, and wavelength coverage. For that purpose, we use simulated broadband ACS, WFC3, and NIRCam data and two-dimensional stellar population synthesis (2D-SPS) to derive the integrated star formation history (SFH) of massive (M_(*) > 10^(10) Mꙩ) simulated galaxies at 1 < z < 4 that evolve into a local M_(*) > 10^(11) Mꙩ galaxy. In particular, we explore the potential of HST and JWST data sets reaching a depth similar to those of the CANDELS and ongoing CEERS observations, respectively, and concentrate on determining the capabilities of this data set for characterizing the first episodes in the SFH of local M_(*) > 10^(11) Mꙩ galaxies by studying their progenitors at z > 1. The 2D-SPS method presented in this paper has been calibrated to robustly recover the cosmic times when the first star formation episodes occurred in massive galaxies, i.e., the first stages in their integrated SFHs. In particular, we discuss the times when the first 1%–50% of their total stellar mass formed in the simulation. We demonstrate that we can recover these ages with typical median systematic offset of less than 5% and scatter around 20%–30%. According to our measurements on Illustris data, we are able to recover that local M_(*) > 10^(11) Mꙩ galaxies would have started their formation by z = 16, forming the first 5% of their stellar mass present at z ∼ 1 by z = 4.5, 10% by z = 3.7, and 25% by z = 2.7.engAtribución 3.0 Españahttps://creativecommons.org/licenses/by/3.0/es/journal articlehttp://dx.doi.org/10.3847/1538-4357/aca8ffhttps://iopscience.iop.org/open access52Star-formationStellar populationsMetallicity relationQuiescent galaxiesMajor mergersEvolutionDustGasIMorphologyAstrofísicaAstronomía (Física)