Temperature fluctuations in photoionized nebulae. II. The effect of inhomogeneous abundances

J. B. Kingdon, G. J. Ferland

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13 Scopus citations


Recent abundance determinations based on recombination lines in several emission-line nebulae yield ionic abundances several times larger than those derived from forbidden lines. These results cast uncertainty over all abundance determinations in such objects. One possible explanation for these discrepancies frequently cited in the literature is the presence of chemical inhomogeneities. We have run a series of photoionization models to examine what effect such inhomogeneities will have on the resulting temperature structure of nebulae. We then derive abundances from these models, utilizing Peimbert's t2 formalism. Our results suggest that, although chemical inhomogeneities may produce nonnegligible biases in abundance determinations in a small number of objects, it is highly unlikely that they can resolve the observed discrepancy for most nebulae. We also stress the importance of continued high spatial resolution observations in nebulae to clarify the presence or absence of inhomogeneities in gaseous nebulae.

Original languageEnglish
Pages (from-to)323-328
Number of pages6
JournalAstrophysical Journal
Issue number1 PART I
StatePublished - 1998


  • ISM: abundances
  • Planetary nebulae: general

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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