AAS Meeting #194 - Chicago, Illinois, May/June 1999
Session 5. Star Formation in Dwarfs and Irregulars
Display, Monday, May 31, 1999, 9:20am-6:30pm, Southwest Exhibit Hall

[Previous] | [Session 5] | [Next]

[5.04] The Oxygen and Nitrogen Abundance of Leo A and GR 8

L. van Zee (NRAO), E. D. Skillman (U. Minnesota), M. P. Haynes (Cornell)

Gas phase abundances are one of the best measures of the intrinsic metallicity of low mass galaxies. We recently obtained low resolution long slit optical spectra of several HII regions in Leo A and GR 8 with the Palomar 5m telescope. Previous studies of the resolved stellar population of Leo A indicated that the stars have metallicities approximately 2% of solar (Tolstoy et al. 1998). Preliminary analysis of the HII region spectra, and that of a planetary nebula, indicates that the gas phase oxygen abundance of Leo A is approximately 3% of solar. This confirms the result of Skillman et al. (1989), who also derived an oxygen abundance for Leo A from a planetary nebula. Similarly, for GR 8 we find a mean oxygen abundance of 5% of solar. For all the HII regions, the derived log(N/O) is -1.5 ± 0.1, as has been found for other low metallicity systems. These new observations of multiple HII regions in Leo A and GR 8 confirm that metals in low mass galaxies are well mixed.

If the author provided an email address or URL for general inquiries, it is a s follows:

[Previous] | [Session 5] | [Next]