2000A&A...354L..41V -
Astronomy and Astrophysics, volume 354, L41-44 (2000/2-1)
The collision strength of the [NeV] infrared fine-structure lines.
VAN HOOF P.A.M., BEINTEMA D.A., VERNER D.A. and FERLAND G.J.
Abstract (from CDS):
The calculation of accurate collision strengths for atomic transitions has been a long standing problem in quantitative spectroscopy. Most modern calculations are based on the R-matrix method and problems pertaining to the use of this method have led to a discussion of the accuracy of these results. More in particular, based on an analysis of the spectra of NGC 3918 and NGC 6302, Clegg et al. (
1987ApJ...314..551C) and Oliva et al. (
1996A&A...305L..21O) have questioned R-matrix calculations for the infrared [NeV] fine-structure transitions. Using improved flux measurements for the [NeV] lines, we show that the conclusion that these collision strengths would be too high, is not correct. The discrepancies found by Clegg et al. (
1987ApJ...314..551C) can be explained by the inaccuracy of the [NeV] 342.6 nm flux they adopted. The discrepancies found by Oliva et al. (
1996A&A...305L..21O) can be explained by the inaccuracy of the LRS flux for the [NeV] 14.32 µm line. Based on the data presented in this paper there is no reason to assume that there are any problems with the R-matrix calculations for Ne
4+ of Lennon & Burke (
1994A&AS..103..273L). We show that the data are accurate at the 30% level or better. This confirms the validity of the close coupling method.
Abstract Copyright:
∼
Journal keyword(s):
atomic data - plasmas - ISM: planetary nebulae: individual: NGC 3918 - ISM: planetary nebulae: individual: NGC 6302 - ISM: planetary nebulae: individual: NGC 7027 - infrared: ISM: lines and bands
Simbad objects:
3
View the references in ADS
To bookmark this query, right click on this link: simbad:2000A&A...354L..41V and select 'bookmark this link' or equivalent in the popup menu