A comparison of the infrared luminosity and ionizing luminosity of selected star forming regions

We have carried out an investigation of the reddest H II regions in the IRAS Point Source Catalog, namely those sources with Y=log(S 25μ /S 12μ ≥1.3, X=log(S 60μ /S 25μ )≥0.8, and S 100μ ≥500 Jy, with the object of determining their stellar content. Of the twenty-four, thirteen are observable at the Very Large Array, and the results of observations of twelve are presented in this paper. The corresponding radio sources, are generally not resolved at 3″ resolution. From this data and other radio data from the literature, as well as estimated distances to the sources, we have calculated the total luminosity of the contained stars from the IRAS data, and plotted this against the total ionization as determined from the radio flux density