He I temperatures in planetary nebulae
Abstract
It is well established that PNe are not thermally homogeneous, beyond what chemically homogeneous photoionization models predict. To discriminate between the different scenarios proposed in the literature, we have determined the temperature based on He I lines for a dozen PNe. We compare these determinations with those derived from the Balmer continua. We find that the He I temperatures agree with the Balmer temperatures and that both are lower than those derived from CELs; suggesting that most PNe are chemically homogeneous.
- Publication:
-
Planetary Nebulae: An Eye to the Future
- Pub Date:
- August 2012
- DOI:
- 10.1017/S1743921312011957
- Bibcode:
- 2012IAUS..283..466P
- Keywords:
-
- planetary nebulae: general;
- ISM: abundances;
- stars: abundances