Calculating Abundances using Electron Temperature and density

[Storm Butler]

Homework Statement

I have a project in my school where we have to write a presentation on a research paper that we find. I picked this article: http://arxiv.org/PS_cache/arxiv/pdf/1003/1003.0416v1.pdf and they start talking about how they find abundances in the nebulae using electron temperature and electron densities. I have no prior knowledge to any astronomy or astrophysics and so not only do i not really know what these two things are but i also don't know how they are used to calculate abundances. Any help i can get in understanding these things would be greatly apreciated. Thanks

Homework Equations

The Attempt at a Solution

 

[NateD]

Electron temperature is a measure of how hot an electron is in a gas or plasma. It is directly related to the energy of the electron and can be determined using spectroscopic measurements. Electron density is the amount of electrons per unit volume in a given area. This can also be determined using spectroscopic measurements. Together, these two values can be used to calculate abundances in nebulae by comparing the data collected from the spectroscopic measurements with theoretical models to predict the abundances.