Bibcode
Vladilo, G.; Centurion, M.
Referencia bibliográfica
Astronomy and Astrophysics (ISSN 0004-6361), vol. 233, no. 1, July 1990, p. 168-176. Research supported by the Caja General de Ahorros de Canarias.
Fecha de publicación:
7
1990
Número de citas
1
Número de citas referidas
1
Descripción
The behavior of the elemental depletions in the ISM along lines of sight
with a very low value of the average hydrogen density is examined. A
simple model in the frame of the McKee-Ostriker (1977) theory has been
used to estimate the line-of-sight filling factors as a function of
n-bar for those interstellar phases in which a significant degree of
ionization is expected. The results show that a substantial fraction of
ionized gas outside classical H II regions may well be present along the
line of sight when n-bar is less than about 0.1/cu cm. If this effect is
neglected, the chemical abundances relative to hydrogen can be
overestimated up to 0.5 dex in logarithm, and the depletions
underestimated by the same amount. A recent IUE survey of interstellar
abundances has been reanalyzed, and it is found that for all the
elements investigated the slope of the correlation D(app)-log n-bar is
steeper in the low-density range. This disagrees with recent models for
elemental depletions.