Dust absorption and the cosmic ultraviolet flux density

We study the evolution of the galaxy UV luminosity density as a function of redshift in the Hubble Deep Field-North (HDF-N). We estimate the amount of energy absorbed by dust and hidden from optical observations by analyzing the HDF-N photometric data with the spectral energy distribution fitting me thod. According to our results, at redshifts of 1 less than or equal to z l ess than or equal to 4.5, the global energy observed in the UV rest frame a t lambda = 1500 Angstrom corresponds to only 7%-11% of the stellar energy o utput, the rest of it being absorbed by dust and reemitted in the far-IR. O ur estimates of the comoving star formation rate density in the universe fr om the extinction-corrected UV emission are consistent with the recent resu lts obtained with Submillimeter Common-User Bolometric Array (SCUBA) at fai nt submillimeter flux levels.