The Star Formation Efficiency During Reionization as Inferred from the Hubble Frontier Fields

Understand

A recent ultraviolet luminosity function (UVLF) analysis in the Hubble Frontier Fields, behind foreground lensing clusters, has helped solidify estimates of the faint-end of the $z \sim 5-9$ UVLF at up to five magnitudes fainter than in the field.

• These measurements provide valuable information regarding the role of low luminosity galaxies in reionizing the universe and can help in calibrating expectations for JWST observations.
• We fit a semi-empirical model to the lensed and previous UVLF data from Hubble.
• This fit constrains the average star formation efficiency (SFE) during reionization, with the lensed UVLF measurements probing halo mass scales as small as $M \sim 2 \times 10^9 {\rm M}_\odot$.