J/A+A/459/307ivo://CDS.VizieR/J/A+A/459/307doi:10.26093/cds/vizier.34590307CDSDel Zanna G.2017-06-21T08:21:54Z2007-07-14T21:11:16ZCDS support team

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

cds-question@unistra.fratomic-physicsFe XVIII produces, in the X-ray and extreme ultraviolet, L-shell (n=2,3,4->2) spectral lines which are among the brightest ones in e.g. solar flares and in Chandra, XMM-Newton spectra of active stars. Recent R-matrix scattering calculations of Witthoeft et al. (2006A&A...446..361W) produce theoretical intensities for some of the brightest transitions increased by large factors (2-3), so it is timely to use these calculations to review and assess all previous line identifications on a quantitative basis. This paper discusses only the most important lines for laboratory and astrophysical applications. Many previous identifications are revised and some tentative ones finally confirmed. Many lines are found to be significantly blended. A considerable number of new identifications are proposed. Excellent agreement between observed and predicted intensities is found in the majority of cases for the first time. It is therefore now possible to use Fe XVIII L-shell lines to measure electron densities in laboratory plasmas and temperatures for a wide range of astrophysical sources.2006A&A...459..307Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/459/307CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/433/731 : Fe XII Benchmarking atomic data (Del Zanna+, 2005)J/A+A/422/731 : Fe X Benchmarking atomic data (Del Zanna+, 2004)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/459/307https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/459/307http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/459/307https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/459/307https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/459/307http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/459/307GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/459/307/table1The configurations used to calculate the energy levels and the radiative datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCodeConfiguration codemeta.codecharConfConfigurationphys.atmol.configuration;instr.setupcharJ/A+A/459/307/table2The details of some of the levels in the most important configurations in Fe XVIIIrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIndexEnergy level indexmeta.idintConfConfiguration and percentage mixingmeta.noteLevelLevelmeta.id;phys.atmol.levelEEnergy (best estimate)cm**-1phys.energy;phys.atmol.leveldoublee_Erms uncertainty on Ebest (1)cm**-1stat.errorintE-Enist? Best energy minus NIST v.3 energy Enist: energy as in the NIST databasecm**-1stat.fit.omc;phys.energyintnullableE-Ecc? Best energy minus CC energy (2)cm**-1stat.fit.omc;phys.energyintnullableJ/A+A/459/307/table3Line identificationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintii levelmeta.idintjj levelmeta.idintRInt12Relative intensity at 10^12^cm^-3^ (1)phspect.line.intensitydoubleRInt19Relative intensity at 10^19^cm^-3^ (1)phspect.line.intensitydoubleLambdaBBest wavelength0.1nmem.wl;phys.atmol.transitionfloate_LambdaB? rms uncertainty on LambdaBest0.1pmstat.errorintnullableLambdaOObserved wavelength0.1nmem.wlfloate_LambdaOrms uncertainty on LambdaObs0.1pmstat.errorintRefReference (3)meta.ref;pos.framecharBlendBlend (2)meta.codecharSameIDReference for same identification (3)meta.ref;pos.frame;phys.atmol.levelcharDiffIDReference for different identification (3)meta.ref;pos.frame;phys.atmol.levelchar