SEARCH AND STUDY OF ULTRACOMPACT H II REGIONS

We present results from a sample of 106 high-luminosity IRAS sources observed with the Very Large Array in the B and C configurations. 96 sources were observed in the X-band and 52 in the K-band, with 42 of them observed at both wavelengths. We also used previously published observations in the C-band for 14 of them. The detection rate of sources with 3.6 cm continuum emission was ≈ 25%, while only 10% have emission at 1.3 cm. In order to investigate the nature of these sources, their physical parameters were calculated mainly using the 3.6 cm continuum emission, and for sources detected at two wavelengths, we used the best fit of three H iiregion models with different geometries. As a final result, we present a catalog of the detected sources, which includes their basic physical parameters for further analysis. The catalog contains 17 ultracompact H II regions and 3 compact H II regions.