Hubble Space Telescope Observations of the Blue Compact Dwarf SBS 0335-052: A Probable Young Galaxy

摘要

We present HST WFPC2 V and I images and GHRS UV spectrophotometry of the spectral regions around Lyα and O I λ1302 of the extremely metal-deficient (Z ～Z/41) blue compact dwarf galaxy (BCD) SBS 0335-052. All the star formation in the BCD occurs in six superstar clusters (SSCs) with ages ≤25 Myr, within a region of ～2" or 520 pc in size. Dust is clearly present and mixed spatially with the SSCs. The SSCs are roughly aligned in the southeast-northwest direction, and there is a systematic increase in reddening of the clusters away from the brightest one. The observed color dependence on position may be the combined effects of differential extinction by dust and color evolution with time due to sequential propagating star formation. There is a supershell of radius ～380 pc, delineating a large supernova cavity.