Publication Date:
2013-08-29
Description:
We demonstrate that when there are gas density variations within a nebula, various line ratios used to determine electron density (Ne) can give different results. When there are non-constant density conditions, it is shown that by using one (average) Ne, significant, systematic biases may occur in the derived chemical abundance ratios. The abundance ratio of a heavy element (when a collisionally excited line is used) to ionized hydrogen may be subject to a large underestimate in the presence of density fluctuations. The more Ne-diagnostic observations made, the more reliable will be the deciphering of the actual Ne variation throughout a nebula.
Keywords:
ASTROPHYSICS
Type:
Astronomical Society of the Pacific, Airborne Astronomy Symposium on the Galactic Ecosystem: From Gas to Stars to Dust, Volume 73; p 115-118
Format:
text