RECOMBINATION LINE OBSERVATIONS IN SOUTHERN HII-REGIONS

Several H II regions were observed in the Instituto Argentina de Radioastronomia (IAR) in the H166-alpha line and 1.4 GHz radio continuum. Resulting physical parameters derived from low-frequency (H166-alpha line) and high-frequency (H110-alpha, H109-alpha, H76-alpha line, made by other authors) observations of H II regions are compared. Low-frequency derived parameters describe better the low-density ionized gas conditions, whereas high-frequency observations are more sensitive to high density ionized gas located in the central parts of the nebulae.