Examinando por Autor "Ceverino, D."

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Acceso Abierto
A Duality in the Origin of Bulges and Spheroidal Galaxies
(IOP Science Publishing, 2021-06-02) Constantin, L.; Pérez González, Pablo G.; Méndez Abreu, J.; Huertas Company, M.; Dimauro, P.; Alcalde Pampliega, B.; Buitrago, F.; Ceverino, D.; Daddi, E.; Domínguez Sánchez, H.; Espino Briones, N.; Hernán Caballero, A.; Koekemoer, A. M.; Rodighiero, G.; Constantin, L. [0000-0001-6820-0015]; Pérez González, P. G. [0000-0003-4528-5639]; Méndez Abreu, J. [0000-0002-8766-2597]; Huertas Company, M. [0000-0002-1416-8483]; Dimauro, P. [0000-0001-7399-2854]; Alcalde Pampliega, B. [0000-0002-4140-0428]; Buitrago, F. [0000-0002-2861-9812]; Caverino, D. [0000-0002-8680-248X]; Daddi, E. [0000-0002-3331-9590]; Domínguez Sánchez, H. [0000-0002-9013-1316]; Espino Briones, N. [0000-0001-6426-3844]; Hernán Caballero, A. [0000-0002-4237-5500]; Koekemoer, A. M. [0000-0002-6610-2048]; Rodighiero, G. [0000-0002-9415-2296]
Studying the resolved stellar populations of the different structural components that build massive galaxies directly unveils their assembly history. We aim at characterizing the stellar population properties of a representative sample of bulges and pure spheroids in massive galaxies (M⋆ > 1010 M⊙) in the GOODS-N field. We take advantage of the spectral and spatial information provided by SHARDS and Hubble Space Telescope data to perform the multi-image spectrophotometric decoupling of the galaxy light. We derive the spectral energy distribution separately for bulges and disks in the redshift range 0.14 < z ≤ 1 with spectral resolution R ∼ 50. Analyzing these spectral energy distributions, we find evidence of a bimodal distribution of bulge formation redshifts. We find that 33% of them present old mass-weighted ages, implying a median formation redshift ${z}_{\mathrm{form}}={6.2}_{-1.7}^{+1.5}$. They are relics of the early universe embedded in disk galaxies. A second wave, dominant in number, accounts for bulges formed at median redshift ${z}_{\mathrm{form}}={1.3}_{-0.6}^{+0.6}$. The oldest (first-wave) bulges are more compact than the youngest. Virtually all pure spheroids (i.e., those without any disk) are coetaneous with the second-wave bulges, presenting a median redshift of formation ${z}_{\mathrm{form}}={1.1}_{-0.3}^{+0.3}$. The two waves of bulge formation are distinguishable not only in terms of stellar ages but also in star formation mode. All first-wave bulges formed fast at z ∼ 6, with typical timescales around 200 Myr. A significant fraction of the second-wave bulges assembled more slowly, with star formation timescales as long as 1 Gyr. The results of this work suggest that the centers of massive disk-like galaxies actually harbor the oldest spheroids formed in the universe.
Acceso Abierto
Reionization and the ISM/Stellar Origins with JWST and ALMA (RIOJA): The Core of the Highest-redshift Galaxy Overdensity at z = 7.88 Confirmed by NIRSpec/JWST
(American Astronomical Society, 2023-09-01) Hashimoto, T., T.; Álvarez-Márquez, J., J.; Fudamoto, Y.; Colina, L.; Inoue, A. K.; Nakazato, Y.; Ceverino, D.; Yoshida, N.; Costantin, Luca; Sugahara, Y.; Gómez Crespo, A.; Blanco-Prieto, C.; Mawatari, K.; Arribas, Santiago; Marques-Chaves, R.; González, E. M.; Bakx, T. J.L.C.; Hagimoto, M.; Hashigaya, T.; Matsuo, H.; Tamura, Y.; Usui, M.; Ren, Y. W.; Japan Society for the Promotion of Science (KAKENHI); Ministerio de Ciencia e Innovación (MICINN); Ministry of Education, Science, Sports and Culture (MEXT); National Astronomical Observatory of Japan (NAOJ); Comunidad de Madrid; The European Space Agency (ESA)
The protoclusters in the epoch of reionization, traced by galaxy overdensity regions, are ideal laboratories for studying the process of stellar assembly and cosmic reionization. We present the spectroscopic confirmation of the core of the most distant protocluster at z = 7.88, A2744-z7p9OD, with the James Webb Space Telescope NIRSpec integral field unit spectroscopy. The core region includes as many as four galaxies detected in [O iii] 4960 and 5008 Å in a small area of ∼3″ × 3″, corresponding to ∼11 × 11 kpc, after the lensing magnification correction. Three member galaxies are also tentatively detected in dust continuum in Atacama Large Millimeter/submillimeter Array Band 6, which is consistent with their red ultraviolet continuum slopes, β ∼ −1.3. The member galaxies have stellar masses in the range of log(M */M ⊙) ∼7.6-9.2 and star formation rates of ∼3-50 M ⊙ yr−1, showing a diversity in their properties. FirstLight cosmological simulations reproduce the physical properties of the member galaxies including the stellar mass, [O iii] luminosity, and dust-to-stellar mass ratio, and predict that the member galaxies are on the verge of merging in a few to several tens of Myr to become a large galaxy with M * ∼ 6 × 109 M ⊙. The presence of a multiple merger and evolved galaxies in the core region of A2744-z7p9OD indicates that environmental effects are already at work 650 Myr after the Big Bang.