The JWST Emission Line Survey (JELS): The sizes and merger fraction of star-forming galaxies during the Epoch of Reionization

Abstract

We used observations from the JWST Emission Line Survey (JELS) to measure the half-light radii () of 23 H-emitting star-forming (SF) galaxies at in the PRIMER/COSMOS field. Galaxy sizes were measured in JWST near-infrared camera observations in rest-frame H (tracing recent star formation) with the F466N and F470N narrow-band filters from JELS, and compared against rest - and -band (tracing established stellar populations) and near-ultraviolet sizes. We find a size-stellar mass () relationship with a slope that is consistent with literature values at lower redshifts, though offset to lower sizes. We observe a large scatter in at low stellar mass (