A search for young galaxies at low redshifts

The results of an ongoing search for nearby galaxies in the state of formation are discussed. The investigation is based on spectroscopy and photometry of blue compact galaxies (BCGs) and blue low surface-brightness galaxies (BLSBGs). Although interesting young-galaxy candidates exist among the BCGs, the dominance of the luminous young stars makes it difficult to make any rapid progress in the understanding of the star formation history of these objects. Stronger constraints on the presence of old stars can be obtained from the study of the BLSBGs. From comparison with models of photometric evolution we find that such galaxies in the sample studied so far have ages in excess of about 2 Gyr. Most of the objects have photometric properties consistent with a high age and a near-constant or slowly increasing star formation rate. The influence of possible selection effects are briefly discussed.