NIRSpec View of the Appearance and Evolution of Balmer Breaks and the Transition from Bursty to Smooth Star Formation Histories from Deep Within the Epoch of Reionization to Cosmic Noon

Understand

Theoretical models and observational evidence suggest that high-redshift galaxies grow under the bursty mode of star formation, with large temporal star formation rate (SFR) fluctuations around some mean value.

• From an observational perspective, it has not been clear at which redshift and stellar population characteristics the transition from bursty to smooth star formation occurs.
• Here, we investigate these using a uniformly reduced sample of NIRSpec prism spectra of 631 galaxies at $3 < z_{\rm spec} < 14$, stacked in 8 redshift and 8 UV slope bins.
• We evaluate the burstiness of star formation histories using the Balmer break strengths as well as the ratios of SFRs as measured from the emission lines to those measured from the UV continua.