Broad Line Emission in Low-metallicity Blue Compact Dwarf Galaxies: Evidence for Stellar Wind, Supernova and Possible Agn Activity

We present spectra of a large sample of low-metallicity blue compact dwarf galaxies which exhibit broad components in their strong emission lines, mainly in Hβ, [O iii] λ4959, 5007 and Hα. Twenty-three spectra have been obtained with the MMT, 14 of which show broad emission. The remaining 21 spectra with broad emission have been selected from the Data Release 5 of the Sloan Digital Sky Survey. The most plausible origin of broad line emission is the evolution of massive stars and their interaction with the circumstellar and interstellar medium. The broad emission with the lowest Hα luminosities (10–10 erg s) The MMT is operated by the MMT Observatory (MMTO), a joint venture of the Smithsonian Institution and the University of Arizona.