Multiwavelength Observations of the Low-Metallicity Blue Compact Dwarf Galaxy SBS 0335−052

New infrared and millimeter observations from Keck, Palomar, ISO, and OVROand archival data from the NRAO VLA and IRAS are presented for the lowmetallicity blue compact dwarf galaxy SBS 0335-052. Mid-infrared imaging showsthis young star-forming system is compact (0.31"; 80 pc) at 12.5 microns. Thelarge Br-gamma equivalent width (235 Angstroms) measured from integral fieldspectroscopy is indicative of a ~5 Myr starburst. The central source appears tobe optically thin in emission, containing both a warm (~80 K) and a hot (~210K) dust component, and the overall interstellar radiation field is quiteintense, about 10,000 times the intensity in the solar neighborhood. COemission is not detected, though the galaxy shows an extremely high global H Igas-to-dust mass ratio, high even for blue compact dwarfs. Finally, thegalaxy's mid-infrared-to-optical and mid-to-near-infrared luminosity ratios arequite high, whereas its far-infrared-to-radio and far-infrared-to-optical fluxratios are surprisingly similar to what is seen in normal star-forminggalaxies. The relatively high bolometric infrared-to-radio ratio is more easilyunderstood in the context of such a young system with negligible nonthermalradio continuum emission. These new lines of evidence may outline featurescommon to primordial galaxies found at high redshift.Comment: 28 pages including 6 figures; accepted for publication in the Astronomical Journa