COSMOS-Web: Intrinsically Luminous z ≳ 10 Galaxy Candidates Test Early Stellar Mass Assembly
Abstrak
We report the discovery of 15 exceptionally luminous 10 ≲ z ≲ 14 candidate galaxies discovered in the first 0.28 deg ^2 of JWST/NIRCam imaging from the COSMOS-Web survey. These sources span rest-frame UV magnitudes of −20.5 > M _UV > −22, and thus constitute the most intrinsically luminous z ≳ 10 candidates identified by JWST to date. Selected via NIRCam imaging, deep ground-based observations corroborate their detection and help significantly constrain their photometric redshifts. We analyze their spectral energy distributions using multiple open-source codes and evaluate the probability of low-redshift solutions; we conclude that 12/15 (80%) are likely genuine z ≳ 10 sources and 3/15 (20%) likely low-redshift contaminants. Three of our z ∼ 12 candidates push the limits of early stellar mass assembly: they have estimated stellar masses ∼ 5 × 10 ^9 M _⊙ , implying an effective stellar baryon fraction of ϵ _⋆ ∼ 0.2−0.5, where ϵ _⋆ ≡ M _⋆ /( f _b M _halo ). The assembly of such stellar reservoirs is made possible due to rapid, burst-driven star formation on timescales < 100 Myr where the star formation rate may far outpace the growth of the underlying dark matter halos. This is supported by the similar volume densities inferred for M _⋆ ∼ 10 ^10 M _⊙ galaxies relative to M _⋆ ∼ 10 ^9 M _⊙ —both about 10 ^−6 Mpc ^−3 —implying they live in halos of comparable mass. At such high redshifts, the duty cycle for starbursts would be of order unity, which could cause the observed change in the shape of the UV luminosity function from a double power law to a Schechter function at z ≈ 8. Spectroscopic redshift confirmation and ensuing constraints of their masses will be critical to understand how, and if, such early massive galaxies push the limits of galaxy formation in the Lambda cold dark matter paradigm.
Topik & Kata Kunci
Penulis (42)
Caitlin M. Casey
Hollis B. Akins
Marko Shuntov
Olivier Ilbert
Louise Paquereau
Maximilien Franco
Christopher C. Hayward
Steven L. Finkelstein
Michael Boylan-Kolchin
Brant E. Robertson
Natalie Allen
Malte Brinch
Olivia R. Cooper
Xuheng Ding
Nicole E. Drakos
Andreas L. Faisst
Seiji Fujimoto
Steven Gillman
Santosh Harish
Michaela Hirschmann
Shuowen Jin
Jeyhan S. Kartaltepe
Anton M. Koekemoer
Vasily Kokorev
Daizhong Liu
Arianna S. Long
Georgios Magdis
Claudia Maraston
Crystal L. Martin
Henry Joy McCracken
Jed McKinney
Bahram Mobasher
Jason Rhodes
R. Michael Rich
David B. Sanders
John D. Silverman
Sune Toft
Aswin P. Vijayan
John R. Weaver
Stephen M. Wilkins
Lilan Yang
Jorge A. Zavala
Akses Cepat
- Tahun Terbit
- 2024
- Sumber Database
- DOAJ
- DOI
- 10.3847/1538-4357/ad2075
- Akses
- Open Access ✓