ASPCS
 
Back to Volume
Paper: Density determination from far-infrared lines
Volume: 73, Airborne Astronomy Symposium on the Galactic Ecosystem: From Gas to Stars to Dust
Page: 115
Authors: Rubin, Robert H.; Simpson, Janet P.; Erickson, Edwin F.; Haas, Michael R.; Lord, Steven D.; Colgan, Sean W. J.
Abstract: 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.
Back to Volume