Abstract
We present a comparison among electron density estimates for planetary nebulae based on different emission-line ratios. We have considered the density indicators [O II] λ3729/λ3726, [S II] λ6716/λ6731, [Cl III] λ5517/λ5537, [Ar IV] λ4711/λ4740, C III] λ1906/λ1909 and [N I] ≈5202/λ5199. The observational data were extracted from the catalogue of Kaler et al. (1997). We verified that statistically Ne[Ar IV] < Ne[Cl III] > Ne[N I] ≈ Ne[O II] < Ne[S II], being these density sensors ordered by the ionization potentials of the parent ions. These differences can be attributed to errors on the atomic parameters used, to the adoption of a same electron temperature for different ions and, what seems to be more probable, to internal variations of density in the studied nebulae.
| Original language | English |
|---|---|
| Pages (from-to) | 134-135 |
| Number of pages | 2 |
| Journal | Revista Mexicana de Astronomia y Astrofisica: Serie de Conferencias |
| Volume | 12 |
| State | Published - 2002 |
| Externally published | Yes |
| Event | Ionized Gaseous Nebulae, a Conference to Celebrate the 60th Birthdays of Silvia Torres-Peimbert and Manuel Peimbert - Mexico City, Mexico Duration: 21 Nov 2000 → 24 Nov 2000 |
Keywords
- Planetary nebulae: general