The Recent Burstiness of Star Formation in Galaxies at z~4.5 from H$\alpha$ Measurements

Understand

The redshift range z=4-6 marks a transition phase between primordial and mature galaxy formation in which galaxies considerably increase their stellar mass, metallicity, and dust content.

• The study of galaxies in this redshift range is therefore important to understand early galaxy formation and the fate of galaxies at later times.
• Here, we investigate the burstiness of the recent star-formation history (SFH) of 221 $z\sim4.5$ main-sequence galaxies at log(M) > 9.7 by comparing their ultra-violet (UV) continuum, H$\alpha$ luminosity, and H$\alpha$ equivalent-width (EW).
• The H$\alpha$ properties are derived from the Spitzer [3.6$\mu$m]-[4.5$\mu$m] broad-band color, thereby properly taking into account model and photometric uncertainties.