Abstract
We have used public JWST/NIRSpec and JWST/NIRCam observations from the CEERS and JADES surveys in order to analyze the star-forming main sequence (SFMS) over the redshift range 1.4 ≤ z < 7. We calculate the star formation rates (SFRs) of the galaxy sample using three approaches: Balmer line luminosity, spectral energy distribution (SED) fitting, and UV luminosity. We find a larger degree of scatter about the SFMS using the Balmer-based SFRs compared to the UV-based SFRs. Because these SFR indicators are sensitive to star formation on different timescales, the difference in scatter may be evidence of bursty star formation histories in the early Universe. We additionally compare the Hα-to-UV luminosity ratio (L(Hα)/ν L ν,1600) for individual galaxies in the sample and find that 29%-52% of the ratios across the sample are poorly described by predictions from a smooth star formation history. Measuring the burstiness of star formation in the early Universe has multiple significant implications, such as deriving accurate physical parameters from SED fitting, explaining the evolution of the UV luminosity function, and providing constraints for subgrid models of feedback in simulations of galaxy formation and evolution.
| Original language | English |
|---|---|
| Article number | 133 |
| Journal | Astrophysical Journal |
| Volume | 977 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 1 2024 |
Bibliographical note
Publisher Copyright:© 2024. The Author(s). Published by the American Astronomical Society.
Funding
We acknowledge the CEERS and JADES teams for the effort to design, execute, and make public observational surveys. We would also like to thank Kate Whitaker, Zoë Haggard, James Bullock and the research group, as well as an anonymous reviewers for useful discussions that improved the quality of this work. We also acknowledge support from NASA grant JWST-GO-01914. This work is based on observations made with the NASA/ESA/CSA James Webb Space Telescope. The data were obtained from the Mikulski Archive for Space Telescopes at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-03127 for JWST. Data were also obtained from the DAWN JWST Archive maintained by the Cosmic Dawn Center. The specific observations analyzed can be accessed via doi:10.17909/z7p0-8481, doi:10.17909/8tdj-8n28, doi:10.17909/gdyc-7g80, and doi:10.17909/fsc4-dt61.
| Funders | Funder number |
|---|---|
| Kate Whitaker | |
| Epsilon Sigma Alpha | |
| National Aeronautics and Space Administration | JWST-GO-01914 |
| National Aeronautics and Space Administration | |
| Central Surgical Association | NAS5-03127 |
| Central Surgical Association |
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science