Bibcode
Rodriguez, M.
Referencia bibliográfica
Astronomy and Astrophysics, v.313, p.L5-L8
Fecha de publicación:
9
1996
Revista
Número de citas
27
Número de citas referidas
25
Descripción
The [Fe II] and [Fe III] emission of seven galactic H II regions is
studied with the aim of comparing their gaseous Fe abundance. The [Fe
II] line intensity ratios are found to behave in a manner that suggests
fluorescence effects. In addition, the uncertainty in the physical
conditions and the ionization stratification of the layers where [Fe II]
emission arises, contribute to render the total Fe abundance implied by
these lines unreliable. The Fe/O abundance ratios are consequently
calculated using the [Fe III] lines and ionization correction factors
derived from the photoionization models available, and are found to be 3
to 30 times lower than the solar value. The close correlation found
between these Fe abundances and the ionization degree suggests that the
local UV radiation field, while determining the ionization equilibrium,
also affects the structure and composition of dust grains coexisting
with the H II gas, thereby releasing Fe gas to the observed extent.