Year: 2001
Type: preprint
Abstract: We discuss the role of the electron temperature in abundance determinations in ionized nebulae (planetary nebulae and giant HII regions). We show that, even when observations provide a direct estimate of Te, abundance determinations may sometimes be significantly in error for reasons other than hypothetical temperature fluctuations or uncertainties in ionization correction factors, and we show striking examples both in the high and the low metallicity regimes. On the other hand, even without a direct measure of Te and under certain conditions, it is possible to give rough estimates (or limits) on the abundances, both in GHRs and in PNe. Although the main mechanisms determining the electron temperature in ionized nebulae have been known for half a century, we emphasize that there are still important problems to be solved. Finally, we advocate for a different description of temperature inhomogeneities than the scheme generally used.
Source: arXiv (Cornell University)
Author: Stasinska, Grazyna
Institution: Universidad Nacional Autónoma de México
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1573771825