Speaker
Apply to be<br> considered for a student <br> award (Yes / No)?
No
Level for award<br> (Hons, MSc, <br> PhD)?
PhD
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
Yes
Abstract content <br> (Max 300 words)<br><a href="http://events.saip.org.za/getFile.py/access?resId=0&materialId=0&confId=34" target="_blank">Formatting &<br>Special chars</a>
The current capture-collision-cascade (C3) models of photoionized nebulae do not explicitly take into account the ionization temperature governing the level of ionization of species in the gas. I have calculated the departure coefficients for a hydrogen nebula using an ionization temperature instead of assuming that it is equal to the electron temperature. This is being done to investigate the known discrepancy that occurs in nebular abundance determinations that are derived from recombination lines and collisionally excited lines, respectively. Radiative transfer effects need to be dealt with differently in this model than when only the electron temperature is taken into account, for which a simple correction can be made for stimulated emission. Stimulated emission is of little importance for optical/IR lines but it can have a significant effect on the populations of radio recombination lines.
Main supervisor (name and email)<br>and his / her institution
Prof DP Smits, smitsdp@unisa.ac.za, Unisa
