J/A+A/574/A29ivo://CDS.VizieR/J/A+A/574/A29doi:10.26093/cds/vizier.35740029CDSWerner K.Rauch T.Kucas S.Kruk J.W.2015-06-21T09:31:38Z2015-01-20T08:07:41ZCDS support team

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

cds-question@unistra.fratomic-physicsThe discovery of technetium (Tc) in the atmospheres of red giants by Merrill (1952ApJ...116...21M) constituted convincing proof that s-process nucleosynthesis is indeed occurring in evolved stars. In principle, Tc should still be present in the atmospheres of hot post-AGB stars and (pre-) white dwarfs although, due to radioactive decay, it should be present in decreasing quantities along post-AGB evolution. The recent discovery of a large number of trans-iron group elements in hot white dwarfs with atomic numbers in the range A=30-56 (Zn to Ba) raises the prospect that Tc (A=43) may also be detected. However, this is currently not feasible because no atomic data exist for ionization stages beyond TcII. As an initial step, we calculated atomic energy levels and oscillator strengths of Tc IV-VI and used these data to compute non-local thermodynamic equilibrium (NLTE) model atmospheres to estimate at which minimum abundance level Tc could be detected. We show that Tc lines can be found in ultraviolet spectra of hot white dwarfs provided Tc is as abundant as other detected trans-Fe elements. We find that radiative levitation can keep Tc in large, easily detectable quantities in the atmosphere. A direct identification of Tc lines is still not feasible because wavelength positions cannot be computed with necessary precision. Laboratory measurements are necessary to overcome this problem. Our results suggest that such efforts are beneficial to the astrophysical community.2015A&A...574A..29Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/574/A29CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/546/A55 : Ge V and Ge VI oscillator strengths (Rauch+, 2012)J/A+A/564/A41 : ZnIV and ZnV oscillator strengths (Rauch+, 2014)J/A+A/566/A10 : Ba V, Ba VI, and Ba VII oscillator strengths (Rauch+, 2014)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/574/A29https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/574/A29http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/574/A29https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/574/A29https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/574/A29http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/574/A29GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/574/A29/table1Tc IV energy levelsIndex[1/4698] Level indexmeta.idintprimaryELevel energycm**-1phys.energy;phys.atmol.leveldoublep[o/e] Level parity (o for odd, e for even)phys.atmol.parity;phys.atmol.levelcharJ[0/12] Angular momentum quantum number Jphys.angMomentumfloatP1[6/100] First percentage (1)%stat.paramintConf1Configuration of the first percentagemeta.notecharterm1Term of the first percentagephys.atmol.termcharP2[1/50]? Second percentage (2)%stat.paramintnullableConf2Configuration of the second percentagemeta.notecharterm2Term of the second percentagephys.atmol.termcharJ/A+A/574/A29/table2Tc IV line transitionsi0[1/4698] Lower level indexmeta.idintp1[o/e] Upper level parityphys.atmol.parity;phys.atmol.levelcharE1Upper level energycm**-1phys.energy;phys.atmol.levelintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[150/500000] Wavelength {lambda} ({AA})0.1nmem.wldoubleE0Lower level energycm**-1phys.energy;phys.atmol.levelintp0[o/e] Lower level parityphys.atmol.parity;phys.atmol.levelcharJ0[0/12] Lower level quantum number Jinstr.det.qefloatJ1[0/12] Upper level quantum number Jinstr.det.qefloati1[1/4698] Upper level indexmeta.idintloggfCalculated HFR oscillator strength value (1)phys.atmol.oscStrength;meta.modelledfloatgATransition probability value (2)s**-1phys.atmol.transProbdoubleJ/A+A/574/A29/table3Tc V energy levelsIndex[1/4698] Level indexmeta.idintprimaryELevel energycm**-1phys.energy;phys.atmol.leveldoublep[o/e] Level parity (o for odd, e for even)phys.atmol.parity;phys.atmol.levelcharJ[0/12] Angular momentum quantum number Jphys.angMomentumfloatP1[6/100] First percentage (1)%stat.paramintConf1Configuration of the first percentagemeta.notecharterm1Term of the first percentagephys.atmol.termcharP2[1/50]? Second percentage (2)%stat.paramintnullableConf2Configuration of the second percentagemeta.notecharterm2Term of the second percentagephys.atmol.termcharJ/A+A/574/A29/table4Tc V line transitionsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[150/500000] Wavelength {lambda} ({AA})0.1nmem.wldoubleE0Lower level energycm**-1phys.energy;phys.atmol.levelintp0[o/e] Lower level parityphys.atmol.parity;phys.atmol.levelcharJ0[0/12] Lower level quantum number Jinstr.det.qefloati0[1/4698] Lower level indexmeta.idintE1Upper level energycm**-1phys.energy;phys.atmol.levelintp1[o/e] Upper level parityphys.atmol.parity;phys.atmol.levelcharJ1[0/12] Upper level quantum number Jinstr.det.qefloati1[1/4698] Upper level indexmeta.idintloggfCalculated HFR oscillator strength value (1)phys.atmol.oscStrength;meta.modelledfloatgATransition probability value (2)s**-1phys.atmol.transProbdoubleJ/A+A/574/A29/table5Tc VI energy levelsIndex[1/4698] Level indexmeta.idintprimaryELevel energycm**-1phys.energy;phys.atmol.leveldoublep[o/e] Level parity (o for odd, e for even)phys.atmol.parity;phys.atmol.levelcharJ[0/12] Angular momentum quantum number Jphys.angMomentumfloatP1[6/100] First percentage (1)%stat.paramintConf1Configuration of the first percentagemeta.notecharterm1Term of the first percentagephys.atmol.termcharP2[1/50]? Second percentage (2)%stat.paramintnullableConf2Configuration of the second percentagemeta.notecharterm2Term of the second percentagephys.atmol.termcharJ/A+A/574/A29/table6Tc VI line transitionsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[150/500000] Wavelength {lambda} ({AA})0.1nmem.wldoubleE0Lower level energycm**-1phys.energy;phys.atmol.levelintp0[o/e] Lower level parityphys.atmol.parity;phys.atmol.levelcharJ0[0/12] Lower level quantum number Jinstr.det.qefloati0[1/4698] Lower level indexmeta.idintE1Upper level energycm**-1phys.energy;phys.atmol.levelintp1[o/e] Upper level parityphys.atmol.parity;phys.atmol.levelcharJ1[0/12] Upper level quantum number Jinstr.det.qefloati1[1/4698] Upper level indexmeta.idintloggfCalculated HFR oscillator strength value (1)phys.atmol.oscStrength;meta.modelledfloatgATransition probability value (2)s**-1phys.atmol.transProbdouble