H-deficient condensations in PNe -- a key to discrepancies in abundance determinations

Details H-deficient condensations in PNe -- a key to discrepancies in abundance determinations H-deficient condensations in PNe -- a key to discrepancies in abundance determinations

Jul 2000

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000hst..prop.8594l&link_type=abstract

HST Proposal ID #8594

Other

Hst Proposal Id #8594 Ism And Circumstellar Matter

Scientific paper

Much of our knowledge of elemental abundances in our own and other galaxies rests on emission line nebulae. Our recent CNO abundance determinations for PNe using optical recombination lines {ORLs} have yielded abundances systematically higher than the `standard' values deduced from UV/optical collisionally excited lines {CELs}, with discrepancies covering a wide range from 1-20. In the extreme case of NGC 6153, multi-waveband analysis has yielded CNO and Ne abundances from ORLs which are all about a factor of ten higher than the CEL values. Temperature fluctuations and density inhomogeneities fail to explain all the available data. Instead our analysis indicates that NGC 6153 may have experienced a recent ejection of H-deficient knots, similar to those observed in the `born-again' PN Abell 30. We propose to obtain deep STIS long-slit spectra for the well-resolved H- deficient knots of A 30 and to search for such knots in NGC 6153. The data will yield the spatially resolved temperature, density and ionization structure of the knots in Abell 30, and, for the first time, accurate ORL C and O abundances for them. The results will lead to a much better understanding of the physics of such knots and their effects on abundance determinations. The observations of NGC 6153 will allow us to test if the observed central peaking of its ORL C and O abundances is a consequence of a central concentration of similar H-deficient knots.

Affiliated with

Also associated with

No associations

Rating

H-deficient condensations in PNe -- a key to discrepancies in abundance determinations 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 H-deficient condensations in PNe -- a key to discrepancies in abundance determinations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and H-deficient condensations in PNe -- a key to discrepancies in abundance determinations will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1720256