IUE UV spectra of giant extragalactic H II regions.

Abstract

The UV spectra (wavelengths between 1200 and 3200 A, resolution of 6 A) of the two extragalactic H II regions NGC 604 and NGC 5471 have been observed with the IUE satellite. The spectra show a continuum energy distribution and absorption lines (often with P Cygni profiles) characteristic of luminous early type stars, with a weak nebular emission spectrum superposed. Some aspects concerning the internal dust extinction and the composition of the dense star clusters exciting the H II complexes are discussed.