Chemical composition of two H II regions in NGC 6822 based on VLT spectroscopy
Por:
Peimbert A., Peimbert M., Ruiz M.T.
Publicada:
1 ene 2005
Resumen:
We present long-slit spectrophotometry of regions Vand X of the Local Group irregular galaxy NGC 6822. The data consist of VLT FORS observations in the 3450-7500 A range. We have obtained electron temperatures and densities using different line intensity ratios. We have derived the He, C, and O abundances relative to H based on re-combination lines; the abundance ratios among these elements are almost independent of the temperature structure of the nebulae. We have also determined the N, O, Ne, S, Cl, and Ar abundances based on collisionally excited lines; the ratios of these abundances relative to that of H depend strongly on the temperature structure of the nebulae. The chemical composition of NGC 6822 V is compared with those of the Sun, the Orion Nebula, NGC 346 in the SMC, and 30 Doradus in the LMC. The value of O/H derived from recombination lines is in good agreement with that derived by Venn and coworkers from two A-type supergiants in NGC 6822. © 2005. The American Astronomical Society, All rights reserved.
Filiaciones:
Peimbert A.:
Instituto de Astronomíe, Universidad Nacional Autónoma de México, Apartado Postal 70-264, México 04510 DF, Mexico
Peimbert M.:
Instituto de Astronomíe, Universidad Nacional Autónoma de México, Apartado Postal 70-264, México 04510 DF, Mexico
Ruiz M.T.:
Departamento de Astronomía, Universidad de Chile, Casilla Postal 36D, Santiago, Chile
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