Unveiling the Distant Universe: Characterizing z ≥ 9 Galaxies in the First Epoch of COSMOS-Web
Abstract We report the identification of 15 galaxy candidates at z ≥ 9 using the initial COSMOS-Web JWST observations over 77 arcmin 2 through four Near Infrared Camera filters (F115W, F150W, F277W, and F444W) with an overlap with the Mid-Infrared Imager (F770W) of 8.7 arcmin 2 . We fit the sample using several publicly available spectral energy distribution (SED) fitting and photometric redshift codes and determine their redshifts between z = 9.3 and z = 10.9 (〈 z 〉 = 10.0), UV magnitudes between M UV = −21.2 and −19.5 (with 〈 M UV 〉 = −20.2), and rest-frame UV slopes (〈 β 〉 = −2.4). These galaxies are, on average, more luminous than most z ≥ 9 candidates discovered by JWST so far in the literature, while exhibiting similar blue colors in their rest-frame UV. The rest-frame UV slopes derived from SED fitting are blue ( β ∼ [−2.0, −2.7]) without reaching extremely blue values as reported in other recent studies at these redshifts. The blue color is consistent with models that suggest the underlying stellar population is not yet fully enriched in metals like similarly luminous galaxies in the lower-redshift Universe. The derived stellar masses with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo stretchy="false">〈</mml:mo> <mml:msub> <mml:mrow> <mml:mi>log</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> </mml:msub> <mml:mo stretchy="false">(</mml:mo> </mml:math> M ⋆ / M ⊙ )〉 ≈ 8–9 are not in tension with the standard Lambda cold dark matter (ΛCDM) model, and our measurement of the volume density of such UV-luminous galaxies aligns well with previously measured values presented in the literature at z ∼ 9–10. Our sample of galaxies, although compact, is significantly resolved.
Authors
- Louise Paquereau (ORCID: https://orcid.org/0000-0003-2397-0360)
- Seiji Fujimoto (ORCID: https://orcid.org/0000-0001-7201-5066)
- Xuheng Ding (ORCID: https://orcid.org/0000-0001-8917-2148)
- Jed McKinney (ORCID: https://orcid.org/0000-0002-6149-8178)
- Crystal L. Martin (ORCID: https://orcid.org/0000-0001-9189-7818)
- Francesco Valentino (ORCID: https://orcid.org/0000-0001-6477-4011)
- Lilan Yang (ORCID: https://orcid.org/0000-0002-8434-880X)
- Stephen M. Wilkins (ORCID: https://orcid.org/0000-0003-3903-6935)
- Guillaume Mahler (ORCID: https://orcid.org/0000-0003-3266-2001)
- Santosh Harish (ORCID: https://orcid.org/0000-0003-0129-2079)
- Marko Shuntov (ORCID: https://orcid.org/0000-0002-7087-0701)
- Hollis B. Akins (ORCID: https://orcid.org/0000-0003-3596-8794)
- G. Gozaliasl (ORCID: https://orcid.org/0000-0002-0236-919X)
- Shuowen Jin
- Vasily Kokorev (ORCID: https://orcid.org/0000-0002-5588-9156)
- Claudia Maraston (ORCID: https://orcid.org/0000-0001-7711-3677)
- A. Renzini (ORCID: https://orcid.org/0000-0002-7093-7355)
- J. D. Silverman (ORCID: https://orcid.org/0000-0002-0000-6977)
- Jorge A. Zavala (ORCID: https://orcid.org/0000-0002-7051-1100)
- Jaclyn B. Champagne (ORCID: https://orcid.org/0000-0002-6184-9097)
- R. Massey (ORCID: https://orcid.org/0000-0002-6085-3780)
- A Enia (ORCID: https://orcid.org/0000-0002-0200-2857)
- Martin Sparre (ORCID: https://orcid.org/0000-0002-9735-3851)
- H. J. McCracken (ORCID: https://orcid.org/0000-0002-9489-7765)
- Aswin P. Vijayan (ORCID: https://orcid.org/0000-0002-1905-4194)
- Christopher C. Hayward (ORCID: https://orcid.org/0000-0003-4073-3236)
- Nicole E. Drakos (ORCID: https://orcid.org/0000-0003-4761-2197)
- Katherine Chworowsky (ORCID: https://orcid.org/0000-0003-4922-0613)
- Anton M. Koekemoer (ORCID: https://orcid.org/0000-0002-6610-2048)
- Bahram Mobasher (ORCID: https://orcid.org/0000-0001-5846-4404)
- R. Michael Rich (ORCID: https://orcid.org/0000-0003-0427-8387)
- Benny Trakhtenbrot (ORCID: https://orcid.org/0000-0002-3683-7297)
- Caitlin M. Casey (ORCID: https://orcid.org/0000-0002-0930-6466)
- O. Ilbert (ORCID: https://orcid.org/0000-0002-7303-4397)
- G. Magdis (ORCID: https://orcid.org/0000-0002-4872-2294)
- Olivia R. Cooper (ORCID: https://orcid.org/0000-0003-3881-1397)
- Christopher C. Lovell (ORCID: https://orcid.org/0000-0001-7964-5933)
- Maximilien Franco (ORCID: https://orcid.org/0000-0002-3560-8599)
- Steven L. Finkelstein (ORCID: https://orcid.org/0000-0001-8519-1130)
- C. Laigle (ORCID: https://orcid.org/0009-0008-5926-818X)
- Jason Rhodes (ORCID: https://orcid.org/0000-0002-4485-8549)
- Kartik Sheth (ORCID: https://orcid.org/0000-0002-5496-4118)
- Micaela B. Bagley (ORCID: https://orcid.org/0000-0002-9921-9218)
- Brant E. Robertson (ORCID: https://orcid.org/0000-0002-4271-0364)
- Arianna S. Long (ORCID: https://orcid.org/0000-0002-7530-8857)
- Steven Gillman (ORCID: https://orcid.org/0000-0001-9885-4589)
- Jeyhan S. Kartaltepe (ORCID: https://orcid.org/0000-0001-9187-3605)
- Daizhong Liu (ORCID: https://orcid.org/0000-0001-9773-7479)
- M. Talia (ORCID: https://orcid.org/0000-0003-4352-2063)
- Andreas L. Faisst (ORCID: https://orcid.org/0000-0002-9382-9832)
- Michaela Hirschmann (ORCID: https://orcid.org/0000-0002-3301-3321)
Institutions
- DAWN Center for Independent Living (US)
- Damien Foundation (BD)
- Technical University of Denmark (DK)
Publication Details
- Journal
- The Astrophysical Journal
- Published
- 2024-09-01
- DOI
- https://doi.org/10.3847/1538-4357/ad5e6a
- Citations
- 26
- Primary Topic
- Galaxies: Formation, Evolution, Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 8.62
Funders
- National Science Foundation
- National Aeronautics and Space Administration
- Research Corporation for Science Advancement
- Space Telescope Science Institute
- Agence Nationale de la Recherche
- Science and Technology Facilities Council