J/A+A/541/A90ivo://CDS.VizieR/J/A+A/541/A90doi:10.26093/cds/vizier.35410090CDSDel Zanna G.Storey P.JBadnell N.R.Mason H.E.2012-09-24T14:24:17Z2012-09-24T12:32:21ZCDS support team

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

cds-question@unistra.fratomic-physicsNew atomic calculations for Fe X are presented. They focus on the need to model the soft X-ray spectrum and in particular the line at 94.0{AA} which is the dominant contribution to the Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA) 94{AA} band in quiet Sun conditions. This line, and others in the band, are due to strong decays from n=4 levels. We present new large-scale R-matrix (up to n=4) and distorted-wave (DW, up to n=6) scattering calculations for electron collisional excitation and compare them to earlier work. We find significant discrepancies with previous calculations. We show that resonances significantly increase the cross-sections for excitations from the ground state to some n=4 levels, in particular to those in the 3s^2^ 3p^4^ 4s configuration. Cascading from higher levels is also important. We suggest a new identification for the 3s 3p^6^ ^2^S_1/2_ - 3s 3p^5^ 4s ^2^P_3/2_ transition, that has a predicted intensity larger than the decays from the 3s^2^ 3p^4^ 4s levels which were identified by Edlen in 1936. The results presented here are relevant to our understanding of transitions from n=4 levels in a wide range of other ions.2012A&A...541A..90Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/541/A90CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/541/A90https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/541/A90http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/541/A90https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/541/A90https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/541/A90http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/541/A90GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapX-raydefaultJ/A+A/541/A90/table1Level energies of the RM4 calculationrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIndex[1/552] Level indexmeta.idintLevelLevel descriptionmeta.note;phys.atmol.levelchar2S+1[2/6] 2S+1 multiplicityphys.atmol.qnintL[0/6] L valuephys.atmol.qnintJ[0.5/6.5] J valuephys.atmol.qnfloatETarget energy (ab initio)cm**-1phys.energy;phys.atmol.leveldoubleJ/A+A/541/A90/table2Transition probabilities and thermally averaged collision strengths for the RM4 calculationrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordinti[1/552] Upper level index of the transitionmeta.idintj[1/552] Lower level index of the transitionmeta.idintAEinstein A coefficients**-1phys.atmol.transProbdoubleCS20kAveraged collision strength at T=2x10^4^Kphys.atmol.collStrengthdoubleCS50kAveraged collision strength at T=5x10^4^Kphys.atmol.collStrengthdoubleCS100kAveraged collision strength at T=1x10^5^Kphys.atmol.collStrengthdoubleCS200kAveraged collision strength at T=2x10^5^Kphys.atmol.collStrengthdoubleCS500kAveraged collision strength at T=5x10^5^Kphys.atmol.collStrengthdoubleCS1MAveraged collision strength at T=1x10^6^Kphys.atmol.collStrengthdoubleCS2MAveraged collision strength at T=2x10^6^Kphys.atmol.collStrengthdoubleCS5MAveraged collision strength at T=5x10^6^Kphys.atmol.collStrengthdoubleCS10MAveraged collision strength at T=1x10^7^Kphys.atmol.collStrengthdoubleCS20MAveraged collision strength at T=2x10^7^Kphys.atmol.collStrengthdoubleElimHigh-energy limitRyphys.energy;phys.atmol.leveldoubleJ/A+A/541/A90/table3Level energies of the DW6 calculationrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIndex[1/1036] Level indexmeta.idintLevelLevel descriptionmeta.note;phys.atmol.levelchar2S+1[2/6] 2S+1 multiplicityphys.atmol.qnintL[SPDFGHI] L valuephys.atmol.qncharJ[0.5/6.5] J valuephys.atmol.qnfloatETarget energy (ab initio)cm**-1phys.energy;phys.atmol.levelintJ/A+A/541/A90/table4Thermally averaged collision strengths for the DW6 calculationrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordinti[1/24] Lower level index of the transitionmeta.idintj[2/1036] Upper level index of the transitionmeta.idintloggfOscillator strength (gf value)phys.atmol.oscStrengthdoubleEEnergy difference between levelsRyphys.energy;arith.diffdoubleCS2kAveraged collision strength at T=2x10^4^Kphys.atmol.collStrengthdoubleCS5kAveraged collision strength at T=5x10^4^Kphys.atmol.collStrengthdoubleCS10kAveraged collision strength at T=1x10^5^Kphys.atmol.collStrengthdoubleCS20kAveraged collision strength at T=2x10^5^Kphys.atmol.collStrengthdoubleCS50kAveraged collision strength at T=5x10^5^Kphys.atmol.collStrengthdoubleCS100kAveraged collision strength at T=1x10^6^Kphys.atmol.collStrengthdoubleCS200kAveraged collision strength at T=2x10^6^Kphys.atmol.collStrengthdoubleCS500kAveraged collision strength at T=5x10^6^Kphys.atmol.collStrengthdoubleCS1MAveraged collision strength at T=1x10^7^Kphys.atmol.collStrengthdoubleCS2MAveraged collision strength at T=2x10^7^Kphys.atmol.collStrengthdoubleJ/A+A/541/A90/table5Transition probabilities for the DW6 calculationrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordinti[0/999] Lower level index of the transitionmeta.idintj[2/1036] Upper level index of the transitionmeta.idintloggfOscillator strength (gf value)phys.atmol.oscStrengthdoubleAEinstein A coefficients**-1phys.atmol.transProbdouble