Star Formation in the NRGb027 and NRGb137 Groups of Galaxies

Forty Halpha and R images of galaxies in the NRGb027 and NRGb137 groups, taken at Kitt Peak National Observatory, are processed and analyzed to determine information about star formation in the group environment; namely where stars are forming and their rates of formation. In the NRGb027 sample, 55% (17/31) of galaxies had detectable Halpha, while in the NRGb137 sample 89% (8/9) galaxies had detectable Halpha. Of the NRGb027 group galaxies that had Halpha, 65% (11/17) showed truncated distributions within r₂₄ while in NRGb137, 12.5% (1/8) were truncated. These results will be compared to results for galaxies in cluster, other group, and isolated environments to determine the effect of galaxy environment on star formation histories.