학술논문
MIDIS: JWST NIRCam and MIRI Unveil the Stellar Population Properties of Lyα Emitters and Lyman-break Galaxies at z ≃ 3–7
Document Type
Author
Iani, Edoardo; Caputi, Karina I.; Rinaldi, Pierluigi; Annunziatella, Marianna; Boogaard, Leindert A.; Östlin, Göran, 1968; Costantin, Luca; Gillman, Steven; Pérez-González, Pablo G.; Colina, Luis; Greve, Thomas R.; Wright, Gillian; Alonso-Herrero, Almudena; Álvarez-Márquez, Javier; Bik, Arjan, 1976; Bosman, Sarah E. I.; Gómez, Alejandro Crespo; Eckart, Andreas; Hjorth, Jens; Jermann, Iris; Labiano, Alvaro; Langeroodi, Danial; Melinder, Jens, 1977; Moutard, Thibaud; Peißker, Florian; Pye, John P.; Tikkanen, Tuomo V.; van der Werf, Paul P.; Walter, Fabian; Henning, Thomas K.; Lagage, Pierre-Olivier; van Dishoeck, Ewine F.
Source
Astrophysical Journal. 963(2)
Subject
Language
English
ISSN
0004-637X
1538-4357
1538-4357
Abstract
We study the stellar population properties of 182 spectroscopically confirmed (MUSE/VLT) Lyα emitters (LAEs) and 450 photometrically selected Lyman-break galaxies (LBGs) at z = 2.8–6.7 in the Hubble Extreme Deep Field. Leveraging the combined power of Hubble Space Telescope and JWST NIRCam and MIRI observations, we analyze their rest-frame UV-through-near-IR spectral energy distributions, with MIRI playing a crucial role in robustly assessing the LAEs' stellar masses and ages. Our LAEs are low-mass objects (log10(M⋆/M⊙)≃7.5) with little or no dust extinction (E(B − V) ≃ 0.1) and a blue UV continuum slope (β ≃ −2.2). While 75% of our LAEs are young (<100 Myr), the remaining 25% have significantly older stellar populations (≥100 Myr). These old LAEs are statistically more massive, less extinct, and have lower specific star formation rate than young LAEs. Besides, they populate the plane of M⋆ versus star formation rate along the main sequence of star-forming galaxies, while young LAEs populate the starburst region. The comparison between the LAEs' properties and those of a stellar-mass-matched sample of LBGs shows no statistical difference between these objects, except for the LBGs' redder UV continuum slope and marginally larger E(B − V) values. Interestingly, 48% of the LBGs have ages <10 Myr and are classified as starbursts, but lack detectable Lyα emission. This is likely due to H i resonant scattering and/or dust-selective extinction. Overall, we find that JWST observations are crucial in determining the properties of LAEs and shedding light on their comparison with LBGs.