Dust absorption and the cosmic ultraviolet flux density
نویسنده
چکیده
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 method. According to our results, at redshifts 1 ≤ z ≤ 4.5, the global energy observed in the UV rest–frame at λ = 1500 Å corresponds to only 7-11 % of the stellar energy output, the rest of it being absorbed by dust and re–emitted in the far– IR. Our estimates of the comoving star formation rate density in the universe from the extinction–corrected UV emission are consistent with the recent results obtained with Submillimeter Common-User Bolometer Array (SCUBA) at faint sub–millimeter flux levels. Subject headings: galaxies: distances and redshifts — galaxies: evolution — ultraviolet: ISM — dust, extinction — methods: data analysis — techniques: photometric Osservatorio Astronomico di Brera, Via Brera 28, 20121 Milano, Italy
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