GA-NIFS: witnessing the complex assembly of a star-forming system at <b> <i>z</i> = 5.7</b>

ABSTRACT We present observations of the $z\sim 5.7$ Lyman-break galaxy HZ10 with the JWST/NIRSpec integral field unit in high and low spectral resolution (G395H, spectral resolving power $R\sim 2700$ and PRISM, $R\sim 100$, respectively), as part of the GA-NIFS programme. By spatially resolving the source (spatial resolution $\sim 0.15{^{\prime \prime }}$ or $\sim 0.9$ kpc), we find three spatially and spectrally distinct regions of line emission along with one region of strong continuum emission, all within a projected distance of $&amp;lt; 10$ kpc. The R2700 data features strong detections in H$\beta$, [O iii] $\lambda \lambda 4959{,}5007$, [N ii] $\lambda \lambda 6548{,}6584$, H$\alpha$, and [S ii] $\lambda \lambda 6716{,}6731$. The R100 data additionally contain a strong detection of the Ly $\alpha$ break, rest-frame UV and optical continuum, and [O ii] $\lambda \lambda 3726{,}3729$. None of the detected lines present strong evidence for active galactic nucleus excitation from line diagnostic diagrams, and no high-ionization lines are detected. Using the detected lines, we constrain the electron density $\left(\rm \log _{10}\left({\it n}_e / cm^{-3}\right)\sim 3\right)$ and metallicity ($\sim 0.5-0.7$ solar) in each component. Spaxel-by-spaxel fits reveal a strong east-west velocity gradient and significant line asymmetries (possibly indicating tidal features or outflows). The western component features a very red UV slope ($\beta _{\rm UV}\sim -0.9$) and significant H $\alpha$ emission, suggesting an evolved population and active star formation. A comparison to high-resolution ($\sim 0.3\,{\rm {arcsec}}$ or $\sim 1.8$ kpc) [${\rm C\, {\small II}}$] $158\, \mu$m imaging obtained with the Atacama Large Millimetre/submillimetre Array (ALMA) reveals areas of dust obscuration. Altogether, these data suggest that HZ10 represents an ongoing merger, with a complex distribution of stars, gas, and dust $&amp;lt; 1$ Gyr after the big bang

Authors

Institutions

Publication Details

Journal
Monthly Notices of the Royal Astronomical Society
Published
2025-06-06
DOI
https://doi.org/10.1093/mnras/staf899
Citations
7
Primary Topic
Astro and Planetary Science
Type
article
Field-Weighted Citation Impact
8.08

Funders

Controls
|||
ALL TIME
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
article

GA-NIFS: witnessing the complex assembly of a star-forming system at z = 5.7

G. Cresci, Francesco D’Eugenio, Santiago Arribas, Bruno Rodríguez Del Pino et al.
7 citations
Monthly Notices of the Royal Astronomical Society
Astro and Planetary Science
8.08
article

GA-NIFS: witnessing the complex assembly of a star-forming system at z = 5.7

G. Cresci, Francesco D’Eugenio, Santiago Arribas, Bruno Rodríguez Del Pino, Michele Perna, R. Maiolino, Jorge González-López, Stefano Carniani, Vicente Villanueva, Chris J. Willott, Rodrigo Herrera-Camus, Torsten Boeker, Gareth C. Jones, Pablo G. Pérez‐González, K. Telikova, S. Charlot, Mirko Curti, Hannah Übler, Isabella Lamperti, Andrew J. Bunker, Manuel Aravena, Eleonora Parlanti
article en
7 citations

Abstract

ABSTRACT We present observations of the $z\sim 5.7$ Lyman-break galaxy HZ10 with the JWST/NIRSpec integral field unit in high and low spectral resolution (G395H, spectral resolving power $R\sim 2700$ and PRISM, $R\sim 100$, respectively), as part of the GA-NIFS programme. By spatially resolving the source (spatial resolution $\sim 0.15{^{\prime \prime }}$ or $\sim 0.9$ kpc), we find three spatially and spectrally distinct regions of line emission along with one region of strong continuum emission, all within a projected distance of $&amp;lt; 10$ kpc. The R2700 data features strong detections in H$\beta$, [O iii] $\lambda \lambda 4959{,}5007$, [N ii] $\lambda \lambda 6548{,}6584$, H$\alpha$, and [S ii] $\lambda \lambda 6716{,}6731$. The R100 data additionally contain a strong detection of the Ly $\alpha$ break, rest-frame UV and optical continuum, and [O ii] $\lambda \lambda 3726{,}3729$. None of the detected lines present strong evidence for active galactic nucleus excitation from line diagnostic diagrams, and no high-ionization lines are detected. Using the detected lines, we constrain the electron density $\left(\rm \log _{10}\left({\it n}_e / cm^{-3}\right)\sim 3\right)$ and metallicity ($\sim 0.5-0.7$ solar) in each component. Spaxel-by-spaxel fits reveal a strong east-west velocity gradient and significant line asymmetries (possibly indicating tidal features or outflows). The western component features a very red UV slope ($\beta _{\rm UV}\sim -0.9$) and significant H $\alpha$ emission, suggesting an evolved population and active star formation. A comparison to high-resolution ($\sim 0.3\,{\rm {arcsec}}$ or $\sim 1.8$ kpc) [${\rm C\, {\small II}}$] $158\, \mu$m imaging obtained with the Atacama Large Millimetre/submillimetre Array (ALMA) reveals areas of dust obscuration. Altogether, these data suggest that HZ10 represents an ongoing merger, with a complex distribution of stars, gas, and dust $&amp;lt; 1$ Gyr after the big bang

Monthly Notices of the Royal Astronomical SocietyVol. 540(4)
Herzberg Institute of Astrophysics (CA), Centre National de la Recherche Scientifique (FR), European Southern Observatory (DE), Scuola Normale Superiore (IT), Pontificia Universidad Católica de Chile (CL), University of Concepción (CL), Carnegie Institution for Science (US), University of Cambridge (GB), Arcetri Astrophysical Observatory (IT), Institut d'Astrophysique de Paris (FR), Sorbonne Université (FR), University of Oxford (GB), Max Planck Institute for Extraterrestrial Physics (DE), Carnegie Observatories (US), Centro de Astrobiología (ES), Istituto Nazionale di Fisica Nucleare, Sezione di Firenze (IT), University College London (GB), Universidad Diego Portales (CL)
UK Research and Innovation, European Commission, Ministerio de Ciencia e Innovación, Agencia Nacional de Investigación y Desarrollo, Science and Technology Facilities Council, Agencia Estatal de Investigación
Life below water
Openalex Percentile: Top 3%
Astro and Planetary Science
8.08
DOIOpen Access PDFOpenAlex
AI Navigator

Ask Laika to Summarize, Analyze, and Connect papers live on the map.

Summarize Papers & Methodologies

Extract key findings, datasets, and comparative methods across publications.

Benchmark Rankings & Visual Analytics

Rank top research institutions, authors, funders, topics, and journals by Field-Weighted Citation Impact (FWCI) and paper volume with instant charts.

Connect Distant Disciplines

Bridge topological clusters on the map to find hidden collaborative intersections.