1998ApJ...506L..89A

Imaging at 1.25 and 2.20 µm has been obtained of the field containing the galaxy (RD1) found at redshift z=5.34 by Dey et al. This galaxy has been detected at 1.25 µm, while the lower redshift (z=4.02) galaxy also found in the same field by Dey et al. was detected at both 1.25 and 2.20 µm. Comparison to stellar population synthesis models indicates that if RD1 is a young (t<10⁸ yr) galaxy, significant reddening (A_V>0.5 mag) is indicated. Combined with observations of other high-redshift systems, these data show that dust is likely to be an important component of young galaxies even at redshifts of z>5. The extinction-corrected monochromatic luminosity of RD1 at 1500 Å is then a factor of about 3 larger than L^*₁₅₀₀ as determined by Dickinson for z∼3 starburst galaxies. The implied star formation rate in RD1, corrected for extinction, is ∼50-100 h^–2₅₀ M_☉.yr^–1.