X iv : a st ro - p h / 97 08 16 3 v 1 1 8 A ug 1 99 7 THE CASE FOR SUBSTANTIAL DUST EXTINCTION AT z ≈ 3
نویسنده
چکیده
Estimates of the total metal production rate (ρ̇Z) and star formation rate at z > 2 are based on Lyman break systems observed in the rest-frame ultraviolet (UV). These observations are very sensitive to dust obscuration. Here I elucidate and refine the Meurer et al. (1997) method for calculating UV obscuration, presenting new relationships which accurately model the dust reprocessing of radiation in local starbursts. The median λ = 1600 Å obscuration factor is ∼ 10 at z ≈ 3 which is shown to be consistent with other constraints on the high-z ρ̇Z . Two tests are proposed to further constrain ρ̇Z at these redshifts.
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