Astronomy and Astrophysics – Astrophysics
Scientific paper
Jan 1996
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1996a%26a...305l..21o&link_type=abstract
Astronomy and Astrophysics, v.305, p.L21
Astronomy and Astrophysics
Astrophysics
20
Atomic Data, Ism: Planetary Nebulae: Individual: Ngc6302, Galaxies: Active, Infrared: General
Scientific paper
Available optical and UV spectral observations of the planetary nebula NGC6302 are analyzed. Temperature diagnostic ratios of high excitation species ([ArV], [NeIV], [NeV]) yield low temperatures typical of photoionized nebulae. The presence of a significant amount of hot, collisionally ionized gas is therefore excluded, and other arguments agree with this conclusion. The fact that observed [NeV] FIR lines are relatively faint cannot be therefore attributed to an unusually large NeV temperature, as in Rowlands et al. (1994: RHH94). Rather, it indicates that the ground state collision strengths are overestimated by a factor of ~3. A major consequence is that available photoionization models of AGN may largely overestimate the strength of [NeV] FIR lines, and this should be considered when interpreting ISO data. More generally, much care should be taken in modeling ground state lines of high-Z species in 'cool' photoionized gas because their collision strengths are often dominated by strong resonances close to the threshold and whose positions may be quite uncertain. This letter is also intended to urge theoretical/experimental work aimed at determining the position of autoionizing levels within {DELTA}S<~3.10^4^cm^-1^ from the ground state of astrophysically abundant ions.
Oliva Ernesto
Pasquali Anna
Reconditi Massimo
No associations
LandOfFree
On [NeV] atomic parameters and physical conditions in NGC 6302. does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with On [NeV] atomic parameters and physical conditions in NGC 6302., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On [NeV] atomic parameters and physical conditions in NGC 6302. will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-967128