Spatially resolved Hα and ionizing photon production efficiency in the lensed galaxy MACS1149-JD1 at a redshift of 9.11
We present MIRI/JWST medium-resolution spectroscopy (MRS) and imaging (MIRIM) of the lensed galaxy MACS1149-JD1 at a redshift of z = 9.1092 ± 0.0002, when the Universe was about 530 Myr old. We detect, for the first time, spatially resolved Hα emission in a galaxy at a redshift above nine. The struc...
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| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
June 2024
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| In: |
Astronomy and astrophysics
Year: 2024, Volume: 686, Pages: 1-11 |
| ISSN: | 1432-0746 |
| DOI: | 10.1051/0004-6361/202347946 |
| Online Access: | Verlag, kostenfrei, Volltext: https://doi.org/10.1051/0004-6361/202347946 Verlag, kostenfrei, Volltext: https://www.aanda.org/articles/aa/abs/2024/06/aa47946-23/aa47946-23.html 
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| Author Notes: | J. Álvarez-Márquez, L. Colina, A. Crespo Gómez, P. Rinaldi, J. Melinder, G. Östlin, M. Annunziatella, A. Labiano, A. Bik, S. Bosman, T.R. Greve, G. Wright, A. Alonso-Herrero, L. Boogaard, R. Azollini, K.I. Caputi, L. Costantin, A. Eckart, M. García-Marín, S. Gillman, J. Hjorth, E. Iani, O. Ilbert, I. Jermann, D. Langeroodi, R. Meyer, F. Peißker, P. Pérez-González, J. P. Pye, T. Tikkanen, M. Topinka, P. van der Werf, F. Walter, Th. Henning, and T. Ray |
| Summary: | We present MIRI/JWST medium-resolution spectroscopy (MRS) and imaging (MIRIM) of the lensed galaxy MACS1149-JD1 at a redshift of z = 9.1092 ± 0.0002, when the Universe was about 530 Myr old. We detect, for the first time, spatially resolved Hα emission in a galaxy at a redshift above nine. The structure of the Hα emitting gas consists of two clumps, S and N, carrying about 60% and 40% of the total flux, respectively. The total Hα luminosity implies an instantaneous star-formation rate in the range of 3.2 ± 0.3 and 5.3 ± 0.4 M⊙ yr−1 for sub-solar and solar metallicities. The ionizing photon production efficiency, log(ζion), shows a spatially resolved structure with values of 25.55 ± 0.03; 25.47 ± 0.03; and 25.91 ± 0.09 Hz erg−1 for the integrated galaxy and clumps S and N, respectively. The Hα rest-frame equivalent width, EW0 (Hα), is 726−182+660 Å for the integrated galaxy, but it presents extreme values of 531−96+300 Å and ≥1951 Å for clumps S and N, respectively. The spatially resolved ionizing photon production efficiency is within the range of values measured in galaxies at a redshift above six and well above the canonical value (25.2 ± 0.1 Hz erg−1). The EW0 (Hα) is a factor of two lower than the predicted value at z = 9.11 based on the extrapolation of the evolution of the EW0 (Hα) with redshifts, ∝(1 + z)2.1, including galaxies detected with JWST. The extreme difference of the EW0 (Hα) for clumps S and N indicates the presence of a recent (< 5 Myr) stellar burst in clump N and a star formation over a larger period of time (e.g., ∼50 Myr) in clump S. The different ages of the stellar population place MACS1149-JD1 and clumps N and S at different locations in the log(ζion) to EW0 (Hα) plane and above the main relation defined from intermediate- and high-redshift (z = 3 − 7) galaxies detected with JWST. Finally, clump S and N show very different Hα kinematics, with velocity dispersions of 56 ± 4 km s−1 and 113 ± 33 km s−1, likely indicating the presence of outflows or increased turbulence in clump N. The dynamical mass Mdyn = (2.4 ± 0.5) × 109 M⊙, obtained from the size of the integrated Hα ionized nebulae and its velocity dispersion, is within the range previously measured with the spatially resolved [OIII]88 μm line. |
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| Item Description: | Online veröffentlicht: 31. Mai 2024 Gesehen am 17.02.2025 |
| Physical Description: | Online Resource |
| ISSN: | 1432-0746 |
| DOI: | 10.1051/0004-6361/202347946 |