The Astrophysical Journal (Jan 2023)
JWST/NIRCam Probes Young Star Clusters in the Reionization Era Sunrise Arc
- Eros Vanzella,
- Adélaïde Claeyssens,
- Brian Welch,
- Angela Adamo,
- Dan Coe,
- Jose M. Diego,
- Guillaume Mahler,
- Gourav Khullar,
- Vasily Kokorev,
- Masamune Oguri,
- Swara Ravindranath,
- Lukas J. Furtak,
- Tiger Yu-Yang Hsiao,
- Abdurro’uf,
- Nir Mandelker,
- Gabriel Brammer,
- Larry D. Bradley,
- Maruša Bradač,
- Christopher J. Conselice,
- Pratika Dayal,
- Mario Nonino,
- Felipe Andrade-Santos,
- Rogier A. Windhorst,
- Nor Pirzkal,
- Keren Sharon,
- S. E. de Mink,
- Seiji Fujimoto,
- Adi Zitrin,
- Jan J. Eldridge,
- Colin Norman
Affiliations
- Eros Vanzella
- ORCiD
- INAF—OAS, Osservatorio di Astrofisica e Scienza dello Spazio di Bologna , via Gobetti 93/3, I-40129 Bologna, Italy ; [email protected]
- Adélaïde Claeyssens
- ORCiD
- Department of Astronomy, Oskar Klein Centre, Stockholm University , AlbaNova University Centre, SE-106 91 Stockholm, Sweden
- Brian Welch
- ORCiD
- Department of Astronomy, University of Maryland , College Park, MD 20742, USA; Observational Cosmology Lab, NASA Goddard Space Flight Center , Greenbelt, MD 20771, USA; Center for Research and Exploration in Space Science and Technology , NASA/GSFC, Greenbelt, MD 20771, USA
- Angela Adamo
- ORCiD
- Department of Astronomy, Oskar Klein Centre, Stockholm University , AlbaNova University Centre, SE-106 91 Stockholm, Sweden
- Dan Coe
- ORCiD
- Space Telescope Science Institute (STScI) , 3700 San Martin Drive, Baltimore, MD 21218, USA; Association of Universities for Research in Astronomy (AURA) , Inc. for the European Space Agency (ESA), USA; Center for Astrophysical Sciences, Department of Physics and Astronomy, The Johns Hopkins University , 3400 North Charles Street, Baltimore, MD 21218, USA
- Jose M. Diego
- ORCiD
- Instituto de Física de Cantabria (CSIC-UC) . Avda. Los Castros s/n. E-39005 Santander, Spain
- Guillaume Mahler
- ORCiD
- Institute for Computational Cosmology, Durham University , South Road, Durham DH1 3LE, UK; Centre for Extragalactic Astronomy, Durham University , South Road, Durham DH1 3LE, UK
- Gourav Khullar
- ORCiD
- Department of Physics and Astronomy and PITT PACC, University of Pittsburgh , Pittsburgh, PA 15260, USA
- Vasily Kokorev
- ORCiD
- Kapteyn Astronomical Institute, University of Groningen , PO Box 800, 9700 AV Groningen, The Netherlands
- Masamune Oguri
- ORCiD
- Center for Frontier Science, Chiba University , 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan; Department of Physics, Graduate School of Science, Chiba University , 1-33 Yayoi-Cho, Inage-Ku, Chiba 263-8522, Japan
- Swara Ravindranath
- ORCiD
- Space Telescope Science Institute (STScI) , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Lukas J. Furtak
- ORCiD
- Physics Department, Ben-Gurion University of the Negev , PO Box 653, Be’er-Sheva 84105, Israel
- Tiger Yu-Yang Hsiao
- ORCiD
- Center for Astrophysical Sciences, Department of Physics and Astronomy, The Johns Hopkins University , 3400 North Charles Street, Baltimore, MD 21218, USA
- Abdurro’uf
- ORCiD
- Space Telescope Science Institute (STScI) , 3700 San Martin Drive, Baltimore, MD 21218, USA; Center for Astrophysical Sciences, Department of Physics and Astronomy, The Johns Hopkins University , 3400 North Charles Street, Baltimore, MD 21218, USA
- Nir Mandelker
- ORCiD
- Centre for Astrophysics and Planetary Science, Racah Institute of Physics, The Hebrew University , Jerusalem, 91904, Israel
- Gabriel Brammer
- ORCiD
- Cosmic Dawn Center (DAWN) , Copenhagen, Denmark; Niels Bohr Institute, University of Copenhagen , Jagtvej 128, Copenhagen, Denmark
- Larry D. Bradley
- ORCiD
- Space Telescope Science Institute (STScI) , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Maruša Bradač
- ORCiD
- Department of Mathematics and Physics, University of Ljubljana , Jadranska ulica 19, SI-1000 Ljubljana, Slovenia; Department of Physics and Astronomy, University of California , Davis, 1 Shields Avenue, Davis, CA 95616, USA
- Christopher J. Conselice
- ORCiD
- Jodrell Bank Centre for Astrophysics, University of Manchester , Oxford Road, Manchester UK
- Pratika Dayal
- ORCiD
- Kapteyn Astronomical Institute, University of Groningen , PO Box 800, 9700 AV Groningen, The Netherlands
- Mario Nonino
- ORCiD
- INAF–Trieste Astronomical Observatory , Via Bazzoni 2, I-34124, Trieste, Italy
- Felipe Andrade-Santos
- ORCiD
- Department of Liberal Arts and Sciences, Berklee College of Music , 7 Haviland Street, Boston, MA 02215, USA; Center for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA
- Rogier A. Windhorst
- ORCiD
- School of Earth and Space Exploration, Arizona State University , Tempe, AZ 85287-1404, USA
- Nor Pirzkal
- ORCiD
- Space Telescope Science Institute (STScI) , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Keren Sharon
- ORCiD
- Department of Astronomy, University of Michigan , 1085 South University Avenue, Ann Arbor, MI 48109, USA
- S. E. de Mink
- ORCiD
- Max Planck Institute for Astrophysics , Karl-Schwarzschild-Strasse 1, D-85748 Garching, Germany; Anton Pannekoek Institute for Astronomy, University of Amsterdam , Science Park 904, 1098XH Amsterdam, The Netherlands
- Seiji Fujimoto
- ORCiD
- Cosmic Dawn Center (DAWN) , Copenhagen, Denmark; Niels Bohr Institute, University of Copenhagen , Jagtvej 128, Copenhagen, Denmark; Department of Astronomy, The University of Texas at Austin , Austin, TX 78712, USA
- Adi Zitrin
- ORCiD
- Physics Department, Ben-Gurion University of the Negev , PO Box 653, Be’er-Sheva 84105, Israel
- Jan J. Eldridge
- ORCiD
- Department of Physics, University of Auckland , Private Bag 92019, Auckland, New Zealand
- Colin Norman
- ORCiD
- Space Telescope Science Institute (STScI) , 3700 San Martin Drive, Baltimore, MD 21218, USA; Center for Astrophysical Sciences, Department of Physics and Astronomy, The Johns Hopkins University , 3400 North Charles Street, Baltimore, MD 21218, USA
- DOI
- https://doi.org/10.3847/1538-4357/acb59a
- Journal volume & issue
-
Vol. 945,
no. 1
p. 53
Abstract
Star cluster formation in the early universe and its contribution to reionization remains largely unconstrained to date. Here we present JWST/NIRCam imaging of the most highly magnified galaxy known at z ∼ 6, the Sunrise arc. We identify six young massive star clusters (YMCs) with measured radii spanning from ∼20 down to ∼1 pc (corrected for lensing magnification), estimated stellar masses of ∼10 ^6–7 M _⊙ , and ages of 1–30 Myr based on SED fitting to photometry measured in eight filters extending to rest frame 7000 Å. The resulting stellar mass surface densities are higher than 1000 M _⊙ pc ^−2 (up to a few 10 ^5 M _⊙ pc ^−2 ), and their inferred dynamical ages qualify the majority of these systems as gravitationally bound stellar clusters. The star cluster ages map the progression of star formation along the arc, with two evolved systems (≳10 Myr old) followed by very young clusters. The youngest stellar clusters (1000 Å rest frame and are hosted in a 200 pc sized star-forming complex. Such a region dominates the ionizing photon production with a high efficiency $\mathrm{log}({\xi }_{\mathrm{ion}}[\mathrm{Hz}\,{\mathrm{erg}}^{-1}])\sim 25.7$ . A significant fraction of the recently formed stellar mass of the galaxy (10%–30%) occurred in these YMCs. We speculate that such sources of ionizing radiation boost the ionizing photon production efficiency, which eventually carves ionized channels that might favor the escape of Lyman continuum radiation. The survival of some of the clusters would make them the progenitors of massive and relatively metal-poor globular clusters in the local universe.
Keywords
