Star formation rates in ring galaxies from IRAS observations

IRAS and optical data for a sample of 26 ring galaxies are analyzed, and it is found that: (1) relatively high average values of far-infrared luminosity L(FIR), infrared to blue luminosity ratio L(FIR)/L(B), and color temperature compared to normal galaxies, implying a high recent star formation rate; (2) evidence that a large fraction of the young stars are located in the rings, indicating a very extended, coherent starburst; and (3) a possible trend of the dispersion of L(FIR) among rings as a function of ring diameter. Thus, within the uncertainties inherent in the study of this relatively small sample, it appears that ring galaxies represent a unique class of nonnuclear coherent starbursts. 45 references