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Title: ON THE O/H, Mg/H, Si/H, AND Fe/H GAS AND DUST ABUNDANCE RATIOS IN GALACTIC AND EXTRAGALACTIC H II REGIONS

Journal Article · · Astrophysical Journal
;  [1]
  1. Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-264, Mexico 04510 D.F. (Mexico)

We derive the Mg/H ratio in the Orion nebula and in 30 Doradus. We also derive the O/H and the Fe/O ratios in the extremely metal-poor galaxy SBS 0335-052 E. We estimate the dust depletions of Mg, Si, and Fe in Galactic and extragalactic H II regions. From these depletions we estimate the fraction of O atoms embedded in dust as a function of the O/H ratio. We find an increasing depletion of O with increasing O/H. The O depletion increases from about 0.08 dex, for the metal poorest H II regions known, to about 0.12 dex, for metal-rich H II regions. This depletion has to be considered to compare nebular with stellar abundances.

OSTI ID:
21471165
Journal Information:
Astrophysical Journal, Vol. 724, Issue 1; Other Information: DOI: 10.1088/0004-637X/724/1/791; ISSN 0004-637X
Country of Publication:
United States
Language:
English