The impact of the visibility of the [O III]λ4363 line on the general properties of H II galaxies in the Local Universe

Abstract

We present a statistical study of a very large sample of H II galaxies taken from the literature. We focus on the differences in several properties between galaxies that show the auroral line [O III] λ4363 and those that do not present this feature in their spectra. It turns out that objects without this auroral line are more luminous, are more metal-rich and present a lower ionization degree. The underlying population is found to be much more important for objects without the [O III] λ4363 line, and the effective temperature of the ionizing star clusters of galaxies not showing the auroral line is probably lower. We also study the subsample of H II galaxies whose properties most closely resemble the properties of the intermediate-redshift population of luminous compact blue galaxies (LCBGs). The objects from this subsample are more similar to the objects not showing the [O III] λ4363 line. It might therefore be expected that the intermediate-redshift population of LCBGs is powered by very massive, yet somewhat aged, star clusters. The oxygen abundance of LCBGs would be greater than the average oxygen abundance of local H II galaxies. © 2005 RAS.