J/A+AS/116/95ivo://CDS.VizieR/J/A+AS/116/95CDSLeisy P.Dennefeld M.1997-12-09T18:07:34Z1997-12-09T19:07:29ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frplanetary-nebulaespectroscopymagellanic-cloudsWe present optical and ultraviolet spectroscopic observations of planetary nebulae (PNe) in the Large (LMC) and the Small Magellanic Clouds (SMC). For the visible spectra with highest S/N, line intensities have been measured to a few tenths of a percent of H_{beta}_. UV spectra are used for the determination of carbon abundances. This paper discusses the CNO cycle and its implications. We show that the CN or ON cycles are more effective with lower initial metallicities and are always complete for typeI nebulae. The latter cannot easily be distinguished from non-type I PNe on the basis of N or He abundance alone, as continuity exists in all of the standard diagrams. From the study of the C abundances, we deduce that the 3rd dredge-up is occurring in all PNe: its efficiency too is higher with lower initial metallicities, offering an easy explanation for the higher number of carbon stars found in metal-deficient galaxies. It is shown that this dredged-up carbon is sometimes transformed into nitrogen by Hot-Bottom Burning, but in a few objects only and not even in all the typeI PNe, which therefore do not form a homogeneous class.1996A&AS..116...95Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+AS/116/95CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+AS/116/95https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+AS/116/95http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+AS/116/95https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+AS/116/95https://vizier.iucaa.in/viz-bin/votable?-source=J/A+AS/116/95http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+AS/116/95GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+AS/116/95/table7SMC PNe observed and corrected line intensitiesFcor[]? Corrected line intensity (1)spect.line.intensity;arith.ratiofloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNamePlanetary nebulae namemeta.id;meta.maincharLambdaWavelengthem.wlintIdentLine identificationmeta.idcharFlambdaExtinction curve value for Lambdaphys.absorptionfloatl_FobsLimit flag on Fobsmeta.code.errorcharFobs[]? Observed line intensity (1)spect.line.intensity;arith.ratiofloatu_FobsUncertainty flag on Fobsmeta.code.errorcharl_FcorLimit flag on Fcormeta.code.errorcharu_FcorUncertainty flag on Fcormeta.code.errorcharJ/A+AS/116/95/table8LMC PNe observed and corrected line intensitiesLambdaWavelengthem.wlintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNamePlanetary nebulae namemeta.id;meta.maincharIdentLine identificationmeta.idcharFlambdaExtinction curve value for Lambdaphys.absorptionfloatl_FobsLimit flag on Fobsmeta.code.errorcharFobs[]? Observed line intensity (1)spect.line.intensity;arith.ratiofloatu_FobsUncertainty flag on Fobsmeta.code.errorcharl_FcorLimit flag on Fcormeta.code.errorcharFcor[]? Corrected line intensity (1)spect.line.intensity;arith.ratiofloatu_FcorUncertainty flag on Fcormeta.code.errorcharJ/A+AS/116/95/table78aFlux, electronic density and temperaturerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNamePlanetary nebula namemeta.id;meta.maincharl_FbLimit flag on Fbmeta.code.errorcharFbFlux Hbeta (10-16 erg/cm2/s-1)1e-16mW.m**-2phot.fluxinte_FbHbeta uncertainty%stat.errorfloatExp1IUE exposure number (first number)meta.id;obs.exposureintExp2[]? IUE exposure number (second number)meta.id;obs.exposureintExp3[]? IUE exposure number (third number)meta.id;obs.exposureintNeElectronic densitycm**-3phys.densityintT(OIII)? [OIII] electronic temperatureKphys.temperature;phys.electronintT(NII)? [NII] electronic temperatureKphys.temperature;phys.electronintCoptLogarithmic extinction constantphys.absorptionfloate_Coptrms uncertainty on Coptstat.errorfloat