| Abstract | Optical and radio observations of global properties are presented for a sample of noninteracting irregular galaxies and some companion objects. The data consist of intermediate-band filter photometry, large aperture spectrophotometry, small aperture spectrophotometry of individual H II regions, and H I 21 cm telescope observations. The galaxies are found to be generally blue, and may not show the classical two-peaked H I 21 cm profile. There is no correlation between the SFR and global gas or abundance parameters, which implies that local, rather than global characteristics govern the star formation process. Metallicities are generally low, comparable to the Magellanic Clouds, and there are absorption features characteristic of cool stars in the spectra regardless of the strength of the SFR in the observed region. Observations appear to agree best with the gas infall model. |
