RUBIES: The Evolution of the Ionization Parameter from 0 < z < 9
The dimensionless ionization parameter, U=q/c, where q is the ratio of the local ionizing photon flux to the local hydrogen density, is a key metric to parameterize nebular conditions. Prior to JWST, the rest-frame optical emission lines and their ratios which trace the ionization parameter (e.g., O32=[OIII]/[OII]) were inaccessible at high redshifts. Here we quantify, for the first time, the evolution of the ionization parameter in galaxies across the last 13 billion years of cosmic time by comparing JWST/NIRSpec PRISM and G395M spectroscopy of 434 galaxies at 3
Authors
- Adèle Plat (ORCID: https://orcid.org/0000-0003-0390-0656)
- Lucie Scharré (ORCID: https://orcid.org/0000-0003-2551-4430)
- Emilie Burnham (ORCID: https://orcid.org/0000-0001-8174-317X)
- Olivia Curtis (ORCID: https://orcid.org/0000-0002-0212-4563)
- Nikko J. Cleri
- Michael V. Maseda
- Zach J. Lewis
- Harley Katz
- Ian McConachie
- Michaela Hirschmann
- Anna de Graaff
- Joel Leja
- Jakob M. Helton
Publication Details
- Journal
- The Open Journal of Astrophysics
- Published
- 2026-09-22
- DOI
- https://doi.org/10.33232/001c.171548
- Primary Topic
- Galaxies: Formation, Evolution, Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 0.00