(a) Night sky spectrum as a function of observed wavelength. The black line shows the night sky spectrum with an arbitrary normalization. The light gray and dark shaded areas indicate the wavelength range of the AO gap and the wavelength range that is not used in this work, respectively. (b) 5σ noise surface brightness (SB) for the typical parameters for optimized NBs (see Sect. 3.2) as a function of redshift (black line). The light gray shaded area indicates the redshift range of the AO gap. (c) M₁₅₀₀ as a function of z for the sample. The large filled blue stars, large open blue stars, and small open blue stars indicate our sources with ZCONF = 2, 3, ZCONF = 1, and ZCONF = 0, respectively. The black dots show nonisolated galaxies (see Sect. 2.2). The black and green lines represent the F775W apparent magnitude cut, and the criteria for the UV-bright sample, respectively.