High-z Stellar Masses Can Be Recovered Robustly with JWST Photometry
The Astrophysical Journal Letters American Astronomical Society 978:2 (2025) l42
21 BALMER JUMP STREET: THE NEBULAR CONTINUUM AT HIGH REDSHIFT AND IMPLICATIONS FOR THE BRIGHT GALAXY PROBLEM, UV CONTINUUM SLOPES, AND EARLY STELLAR POPULATIONS
Open Journal of Astrophysics 8 (2025)
Abstract:
We study, from both a theoretical and observational perspective, the physical origin and spectro-scopic impact of extreme nebular emission in high-redshift galaxies. The nebular continuum, which can appear during an extreme starburst, is of particular importance as it tends to redden UV slopes and has a significant contribution to the UV luminosities of galaxies. Furthermore, its shape can be used to infer the gas density and temperature of the interstellar medium. First, we provide a theoretical background, showing how different stellar populations (SPS models, initial mass functions (IMFs), and stellar temperatures) and nebular conditions impact observed galaxy spectra. We demonstrate that, for systems with strong nebular continuum emission, 1) UV fluxes can increase by up to 0.7 magnitudes (or more in the case of hot/massive stars) above the stellar continuum, which may help reconcile the surprising abundance of bright high-redshift galaxies and the elevated UV luminosity density at z ≿ 10, 2) at high gas densities, UV slopes can redden from β ≾ −2.5 to β ∼ −1, 3) observational measurements of ξImpact of star formation models on the growth of simulated galaxies at high redshifts
Astronomy & Astrophysics EDP Sciences (2024)
Early Bright Galaxies from Helium Enhancements in High-Redshift Star Clusters
The Open Journal of Astrophysics Maynooth University 7 (2024)
A public grid of radiative transfer simulations for Lyα and metal lines in idealised galactic outflows
Astronomy & Astrophysics EDP Sciences 691 (2024) a213