Year: 2024
Type: article
Abstract: We present the first statistical investigation of spatially resolved emission-line properties in a sample of 63 low-mass galaxies at 4 ≤ z < 10 using James Webb Space Telescope (JWST)/NIRSpec Micro Shutter Assembly (MSA) data from the JWST Advanced Deep Extragalactic (JADES) survey, focusing on deep, spatially resolved spectroscopy in the GOODS-S extragalactic field. By performing a stacking of the 2D spectra of the galaxies in our sample, we find an increasing or flat radial trend with increasing radius for [O III]λ5007/Hβ and a decreasing trend for the blended spectral complex (Hη + [Ne III]λ3869 + He Iλ3889 + Hζ)/[O II]λ3727 (3−4σ significance). These results are still valid when stacking the sample in two redshift bins (i.e. 4 ≤ z < 5.5 and 5.5 ≤ z < 10). The comparison with star-formation photoionisation models suggests that the ionisation parameter increases by ∼0.5 dex with redshift. Under the hypothesis that radial variations in (Hη + [Ne III]λ3869 + He Iλ3889 + Hζ)/[O II]λ3727 are dominated by trends in [Ne III]λ3869/[O II]λ3727, we find a tentative metallicity gradient that increases with radius (i.e. ‘inverted’) in both redshift bins. Moreover, our analysis reveals strong negative gradients for the equivalent width of Hβ (7σ significance). This trend persists even after removing known active galactic nucleus candidates, and is therefore consistent with a radial gradient primarily in stellar age and secondarily in metallicity. Taken together, our results suggest that the sample is dominated by active central star formation, with possibly inverted metallicity gradients sustained by recent episodes of accretion of pristine gas or strong radial flows. Deeper observations and larger samples are needed to confirm these preliminary results and to validate our interpretation.
Authors: Roberta Tripodi, Francesco D’Eugenio, Roberto Maiolino, Mirko Curti, Jan Scholtz, Sandro Tacchella, Cosimo Marconcini, Andrew J. Bunker, James A. A. Trussler, Alex J. Cameron, Santiago Arribas, William M. Baker, Maruša Bradač, Stefano Carniani, Stéphane Charlot, Xihan Ji, Zhiyuan Ji, Brant Robertson, Hannah Übler, Giacomo Venturi, Christopher N. A. Willmer, Joris Witstok
Institutions: European Southern Observatory, University of Cambridge, Arcetri Astrophysical Observatory, University of Florence, University of Oxford, University of Manchester, Centro de Astrobiología, University of Ljubljana, Scuola Normale Superiore, Centre National de la Recherche Scientifique, Institut d'Astrophysique de Paris, Sorbonne Université, University of Arizona, University of California, Santa Cruz
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, National Aeronautics and Space Administration, University of California, Santa Cruz, University of Arizona, Space Telescope Science Institute, UK Research and Innovation, European Commission, Ministero dell’Istruzione, dell’Università e della Ricerca, Isaac Newton Trust, Ministerio de Ciencia e Innovación, Science and Technology Facilities Council, Agencia Estatal de Investigación, H2020 European Research Council
Awards: G103270039, G1166668239, G1175115578, G1325949514, G1338664626, G1577046871, G1849103467, G1855990336, G2144673021, G2262748287, G2309174360, G256731684, G2601397997, G2660406951, Black hole winds and the baryon life cycle of galaxies: the stone-guest at the galaxy evolution supper, G300979063, The Formation of the First Galaxies and Reionization with the James Webb Space Telescope, G3228396264, G3275705967, G3340416472, G3452655474, G3480869486, G3660973570, G3681454997, G4042783231, G425668148, G430777504, G434337789, G4501905872, G4915654406, G5080475149, G5195188938, G531848386, G5368796297, G5421974903, G5568641063, G6307073466, G6464745819, G7084143925, G7736885172, G8252591933, MRI: Acquisition of a High Performance Computer for Computational Science at UC Santa Cruz, G8931419319, G971458805, G99296377
OpenAlex ID: W6940939030
FWCI:
Cites:
Cited by:
Related to: