Abstract
We present optical and radio observations of global properties for a sample of noninteracting irregular galaxies and a few comparison objects. Program galaxies were chosen primarily on the basis of their blue colors and thus may be expected to represent systems with high rates of star formation. The data consist of 40'' aperture photometry through intermediate-band filters, 25'' aperture spectrophotometry in the region 3500--5900 A, spectrophotometry of individual H II regions primarily from 4500--7500 A;o, and 21 cm H I observations. From the filter photometry we determine a Mg index and a reddening-free color parameter Q. An iterative population synthesis technique is applied to the large aperture spectra in order to separate H..beta.. emission from absorption, and a star formation rate (SFR) is estimated from the number of ionizing photons coupled with a Miller and Scalo initial mass function. Line fluxes are used to determine the abundance ratios O/H and N/sup +//S/sup +/, and the radio data give information on gas masses and kinematics.
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