Physical parameters of low-ionization knots and jets in PNe: NGC 7009, K 4-47, and NGC 6543

Gonçcalves, D. R.
Referencia bibliográfica

Astrophysics and Space Science, v. 287, Issue 1, p. 245-248 (2003).

Fecha de publicación:
2003
Número de autores
1
Número de autores del IAC
1
Número de citas
1
Número de citas referidas
1
Descripción
In addition to the large-scale outflows, which form their round, elliptical, and bipolar shells, planetary nebulae (PNe) also have, usually on smaller scales, pairs of highly collimated outflows, or jets. These jets, as well as the pairs of knots that appear at their tips (very prominent in the low-ionization emission lines), are the subject of the present study. We show our results on the temperatures and densities of jets and knots, compare these physical parameters with those of the main shells of PNe, and compare them with theoretical model predictions. We note particularly that the knots at the tips of the jets are not denser than the jets, and that neither is their emission collisionally excited, as one would expect if they were by-products of the associated supersonic jets.