A massive interacting galaxy 510 million years after the Big Bang

This work is based on observations made with JWST, which is run jointly by NASA, the European Space Agency and the Canadian Space Agency. The data were obtained from the Mikulski Archive for Space Telescopes at STScI, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127 for JWST. These observations are associated with programmes JWST-ERS-1324 and JWST-DDT-2756. We acknowledge financial support from NASA (Grant No. JWST-ERS-1324). K.B., M.T., B.M. and N.D. acknowledge support from the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013. K.G. and T.N. acknowledge support from Australian Research Council Laureate Fellowship FL180100060. B.M. acknowledges support from the Australian Government Research Training Program Scholarships and the Jean E Laby Foundation. We acknowledge financial support through grants PRIN-MIUR 2017WSCC32 and 2020SKSTHZ. M.B. acknowledges support from the European Research Council (Grant No. FIRSTLIGHT) and from the Slovenian national research agency (Grant Nos. N1-0238 and P1-0188). C.A.M. acknowledges support from Villum Fonden (Grant No. 37459) and the Carlsberg Foundation (Grant No. CF22-1322). The Cosmic Dawn Center is funded by the Danish National Research Foundation (Grant No. DNRF140). We acknowledge support from the Italian National Institute for Astrophysics (INAF; Large Grant 2022 for Extragalactic Surveys with JWST, PI Pentericci). E.V. acknowledges support from the INAF (GO Grant 2022 for The revolution is around the corner: JWST will probe globular cluster precursors and Population III stellar clusters at cosmic dawn). M.C. acknowledges support from INAF (a mini grant for Reionization and fundamental cosmology with high-redshift galaxies). P.S. acknowledges an INAF mini grant 2022 for The evolution of passive galaxies through cosmic time. D.M. acknowledges financial support from programme HST-GO-17231, provided through a grant from STScI under NASA contract NAS5-26555.

Our analysis makes use of several publicly available codes. The NIRSpec data were reduced using the msaexp code, which can be found here: https://github.com/gbrammer/msaexp. The data reduction of the NIRCam images were performed with the official STScI JWST pipeline, which can be found here: https://github.com/spacetelescope/jwst. The SED fitting analyses were performed with BAGPIPES, the latest version of which (including the templates used here) is available at https://bagpipes.readthedocs.io/en/latest/. We modelled the observed spectral emission lines using the specutils packages within Python, which can be found at https://specutils.readthedocs.io/en/stable/. We performed aperture photometry on the direct imaging using the photutils packages within Python, which can be found at https://photutils.readthedocs.io/en/stable. Galactic morphological parameters were measured using the GLASS in-house JWSTmorph package, which is publicly available at https://github.com/Anthony96/JWSTmorph.git. All other code generated throughout the analysis is available from the corresponding author on request.

The authors declare no competing interests.