2002AJ....124.1995P

We analyze the infrared (6-100 µm) spectral energy distribution of the blue compact dwarf and metal-poor (Z=Z_☉/41) galaxy SBS 0335-052. With the help of DUSTY, a program that solves the radiation transfer equations in a spherical environment, we evaluate that the infrared emission of SBS 0335-052 is produced by an embedded super-star cluster hidden under 10⁵ M_☉of dust, causing 30 mag of visual extinction. This implies that one cannot detect any stellar emission from the 2x10⁶ M_☉stellar cluster even at near-infrared wavelengths. The derived grain size distribution departs markedly from the widely accepted size distribution inferred for dust in our galaxy (the so-called MRN distribution) but resembles what is seen around AGNs, namely, an absence of polycyclic aromatic hydrocarbon and smaller grains, as well as grains that grow to larger sizes (around 1 µm). The fact that a significant amount of dust is present in such a low-metallicity galaxy, hiding from UV and optical view most of the star formation activity in the galaxy, and that the dust size distribution cannot be reproduced by a standard galactic law should be borne in mind when interpreting the spectrum of primeval galaxies.