MOSEL survey: Unwrapping the Epoch of Reionization through mimic galaxies at Cosmic Noon

The nature of the first galaxies that reionized the universe during the Epoch of Reionization (EoR) remains unclear. Attempts to directly determine spectral properties of these early galaxies are affected by both limited photometric constraints across the spectrum and by the opacity of the intergalactic medium (IGM) to the Lyman Continuum (LyC) at high redshift. We approach this by analysing properties of analogous extreme emission line galaxies (EELGs, [OIII]+Hbeta EW >400 Angstrom) at 2.55.5 observed with the James Webb Space Telesope (JWST) with self-consistent spectral energy distribution fitting methodology. This work focuses on the comparison of their UV slopes (β_P), ionizing photon production efficiencies ξ_ion, star formation rates and dust properties to determine the effectiveness of this analogue selection technique. We report the median ionizing photon production efficiencies as log_10(ξ_ion/(Hz erg^-1))=25.14^+0.06_-0.04,25.16^+0.06_-0.05,25.16^+0.04_-0.05,25.18^+0.06_-0.07 for our ZFOURGE control, ZFOURGE EELG, JADES and CEERS samples respectively. ZFOURGE EELGs are 0.57 dex lower in stellar mass and have half the dust extinction, compared to their ZFOURGE control counterparts. They also have a similar specific star formation rates and β_P to the z>5.5 samples. We find that EELGs at low redshift (2.5更多