Fig. 2: Ionizing-photon production efficiency.
From: A luminous and young galaxy at z = 12.33 revealed by a JWST/MIRI detection of Hα and [O iii]
Inferred ionizing-photon production efficiency ξion for GHZ2 assuming a conservative dust attenuation A(V) = 0.3 mag and escape fraction fesc = 0 (illustrated with the solid dark red hexagon). For comparison, we show the inferred value for zero dust attenuation (light red) and estimated values for other samples (average values70 and individual measurements71,72,73,74,75,76,77,78), along with the ξion redshift evolution from ref. 57 for two different stellar masses (solid and dashed lines). Error bars represent 1σ errors of individual measurements or the scatter of the measurements for the sample average. The bright Hα emission of GHZ2 implies high ionizing-photon production, probably above the typical values adopted for galaxies contributing to the reionization process79. HAE, Hα emitter; LAE, Lyman α emitter; LBG, Lyman break galaxy.
