RIOJA: The dusty outflows and density-complex interstellar medium in the N-enhanced lensed galaxy RXCJ2248-ID at z = 6.1
16 affiliations
- 1Centro de Astrobiología (CAB), CSIC-INTA
- 2Space Telescope Science Institute (STScI)
- 3Department of Physics, Graduate School of Science, Nagoya University
- 4Division of Physics, Faculty of Pure and Applied Sciences, University of Tsukuba
- 5Geneva Observatory, Department of Astronomy, University of Geneva
- 6Department of Physics, The University of Tokyo
- 7Center for Computational Astrophysics, Flatiron Institute
- 8Department of Physics, School of Advanced Science and Engineering, Faculty of Science and Engineering, Waseda University
- 9Waseda Research Institute for Science and Engineering, Faculty of Science and Engineering, Waseda University
- 10Departamento de Fisica Teorica, Modulo 8, Facultad de Ciencias, Universidad Autonoma de Madrid
- 11CIAFF, Facultad de Ciencias, Universidad Autonoma de Madrid
- 12Kavli Institute for the Physics and Mathematics of the Universe (WPI), UT Institute for Advanced Study, The University of Tokyo
- 13Research Center for the Early Universe, School of Science, The University of Tokyo
- 14Institute for Cosmic Ray Research, The University of Tokyo
- 15Cosmic Dawn Center (DAWN), Niels Bohr Institute, University of Copenhagen
- 16Kitami Institute of Technology
Abstract
We present an analysis on the kinematics and physical properties of the ionised gas in the lensed galaxy RXCJ2248-ID at z = 6.105 based on high-resolution JWST NIRSpec/IFU data. This source is a nitrogen-rich high- z galaxy showing a compact morphological structure and high star formation and stellar surface densities. The magnification factor of the observed image of the source (ID3, μ = 5.3) along with the rich dataset available, including NIRSpec and ALMA spectroscopy, makes this target an ideal benchmark to study the physical properties of nitrogen-rich galaxies. In this work, we use the large number of optical lines detected at a high signal-to-noise (S/N) in our NIRSpec high-resolution ( R = 2700) integral field spectra to analyse potential differences in kinematics, dust distribution, and electron temperature and density. In addition, we combine our data with available ALMA observations to derive the optical-to-far-IR [O III ] λ 5008/[O III ] 88 μm ratio in order to estimate the electron density of the O ⁺⁺ regions. Our analysis revealed a high electron temperature ( T e ∼ 30 000 K) in the ionised gas independent of the ionisation level. We measured a wide range in the electron densities of the ionised interstelllar medium (ISM) from our [O III ] λ 5008/[O III ] 88 μm and [Ar IV ] λ 4713/[Ar IV ] λ 4742 ratios (log( n e [cm ⁻³ ]) ∼ 2.7−3.8) and previous values (i.e. 4.8 < log( n e [cm ⁻³ ]) < 5.5) based on high-ionisation rest-UV emission lines. The ionised gas appears to be clumpy with a low filling factor ranging from about 10% to 0.2% for the low- and high-density clouds. In addition, we observed a very complex ISM kinematic structure traced by the [O III ] λ 5008 and H α lines. Concretely, we derived the presence of two distinct broad and very broad components (FWHM ∼ 210−250 and ∼1000−1500 km s ⁻¹ ) in addition to the systemic component (FWHM ∼ 60−70 km s ⁻¹ ). These broad components are heavily extinct ( A V ∼ 1.5 and 2.5, respectively), based on their Balmer decrements, while the gas associated with the narrow component is consistent with no extinction. The maximal velocities of these outflows (∼115−500 km s ⁻¹ ) are such that a fraction of the total outflowing gas (0.16−2.1 × 10 ⁷ M ⊙ ) could escape into the intergalactic medium. The rest of the gas will fall back to the central regions, remaining available for additional star formation episodes. The presence of dusty outflows and a clumpy (i.e. low filling factor) ISM give support to the attenuation-free scenario proposed to explain the high- z UV-bright compact galaxies such as RXCJ2248-ID. On the other hand, the high densities in the ISM together with the high sta formation rate surface brightness and the amount of returning outflowing mass give support to the feedback-free starburst scenario.
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BibTeX
@article{gomez2026rioja,
title = {{RIOJA: The dusty outflows and density-complex interstellar medium in the N-enhanced lensed galaxy RXCJ2248-ID at z = 6.1}},
author = {A. Crespo Gómez and Y. Tamura and L. Colina and J. Álvarez-Márquez and T. Hashimoto and R. Marques-Chaves and Y. Nakazato and C. Blanco-Prieto and K. Sunaga and L. Costantin and A. K. Inoue and A. Hamada and S. Arribas and D. Ceverino and M. Hagimoto and K. Mawatari and W. Osone and Y. Sugahara and N. Yoshida and Y. Harikane and M. M. Lee and A. Taniguchi and H. Umehata},
journal = {Astronomy \& Astrophysics},
year = {2026},
month = nov,
doi = {10.1051/0004-6361/202558012},
url = {https://www.aanda.org/10.1051/0004-6361/202558012},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - RIOJA: The dusty outflows and density-complex interstellar medium in the N-enhanced lensed galaxy RXCJ2248-ID at z = 6.1
AU - A. Crespo Gómez
AU - Y. Tamura
AU - L. Colina
AU - J. Álvarez-Márquez
AU - T. Hashimoto
AU - R. Marques-Chaves
AU - Y. Nakazato
AU - C. Blanco-Prieto
AU - K. Sunaga
AU - L. Costantin
AU - A. K. Inoue
AU - A. Hamada
AU - S. Arribas
AU - D. Ceverino
AU - M. Hagimoto
AU - K. Mawatari
AU - W. Osone
AU - Y. Sugahara
AU - N. Yoshida
AU - Y. Harikane
AU - M. M. Lee
AU - A. Taniguchi
AU - H. Umehata
PY - 2026
DA - 2026/11/06
JO - Astronomy & Astrophysics
DO - 10.1051/0004-6361/202558012
UR - https://www.aanda.org/10.1051/0004-6361/202558012
AB - We present an analysis on the kinematics and physical properties of the ionised gas in the lensed galaxy RXCJ2248-ID at z = 6.105 based on high-resolution JWST NIRSpec/IFU data. This source is a nitrogen-rich high- z galaxy showing a compact morphological structure and high star formation and stellar surface densities. The magnification factor of the observed image of the source (ID3, μ = 5.3) along with the rich dataset available, including NIRSpec and ALMA spectroscopy, makes this target an ideal benchmark to study the physical properties of nitrogen-rich galaxies. In this work, we use the large number of optical lines detected at a high signal-to-noise (S/N) in our NIRSpec high-resolution ( R = 2700) integral field spectra to analyse potential differences in kinematics, dust distribution, and electron temperature and density. In addition, we combine our data with available ALMA observations to derive the optical-to-far-IR [O III ] λ 5008/[O III ] 88 μm ratio in order to estimate the electron density of the O ⁺⁺ regions. Our analysis revealed a high electron temperature ( T e ∼ 30 000 K) in the ionised gas independent of the ionisation level. We measured a wide range in the electron densities of the ionised interstelllar medium (ISM) from our [O III ] λ 5008/[O III ] 88 μm and [Ar IV ] λ 4713/[Ar IV ] λ 4742 ratios (log( n e [cm ⁻³ ]) ∼ 2.7−3.8) and previous values (i.e. 4.8 < log( n e [cm ⁻³ ]) < 5.5) based on high-ionisation rest-UV emission lines. The ionised gas appears to be clumpy with a low filling factor ranging from about 10% to 0.2% for the low- and high-density clouds. In addition, we observed a very complex ISM kinematic structure traced by the [O III ] λ 5008 and H α lines. Concretely, we derived the presence of two distinct broad and very broad components (FWHM ∼ 210−250 and ∼1000−1500 km s ⁻¹ ) in addition to the systemic component (FWHM ∼ 60−70 km s ⁻¹ ). These broad components are heavily extinct ( A V ∼ 1.5 and 2.5, respectively), based on their Balmer decrements, while the gas associated with the narrow component is consistent with no extinction. The maximal velocities of these outflows (∼115−500 km s ⁻¹ ) are such that a fraction of the total outflowing gas (0.16−2.1 × 10 ⁷ M ⊙ ) could escape into the intergalactic medium. The rest of the gas will fall back to the central regions, remaining available for additional star formation episodes. The presence of dusty outflows and a clumpy (i.e. low filling factor) ISM give support to the attenuation-free scenario proposed to explain the high- z UV-bright compact galaxies such as RXCJ2248-ID. On the other hand, the high densities in the ISM together with the high sta formation rate surface brightness and the amount of returning outflowing mass give support to the feedback-free starburst scenario.
SN - 0004-6361
SN - 1432-0746
ER -