The UKIRT Infrared Deep Sky Survey ZY JHK photometric system: passbands and synthetic colours |
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Authors: | P. C. Hewett S. J. Warren S. K. Leggett S. T. Hodgkin |
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Affiliation: | Departamento de Física Teórica, Universidad Autónoma de Madrid, Carretera de Colmenar Viejo km 15.600, Madrid 28049, Spain |
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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. |
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Keywords: | galaxies: abundances galaxies: evolution galaxies: starburst galaxies: stellar content |
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