J/ApJ/849/5ivo://CDS.VizieR/J/ApJ/849/5doi:10.26093/cds/vizier.18490005CDSSchippers S.Martins M.Beerwerth R.Bari S.Holste K.Schubert K.,Viefhaus J.Savin D.W.Fritzsche S.Muller A.2018-09-19T07:17:33Z2018-07-16T15:19:47ZCDS support team

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

cds-question@unistra.fratomic-physicsAbsolute cross-sections for m-fold photoionization (m=1, ..., 6) of Fe+ by a single photon were measured employing the photon-ion merged-beams setup PIPE at the PETRA III synchrotron light source, operated by DESY in Hamburg, Germany. Photon energies were in the range 680-920eV, which covers the photoionization resonances associated with 2p and 2s excitation to higher atomic shells as well as the thresholds for 2p and 2s ionization. The corresponding resonance positions were measured with an uncertainty of +/-0.2eV. The cross-section for Fe+ photoabsorption is derived as the sum of the individually measured cross-sections for m-fold ionization. Calculations of the Fe+ absorption cross-sections were carried out using two different theoretical approaches, Hartree-Fock including relativistic extensions and fully relativistic multiconfiguration Dirac-Fock. Apart from overall energy shifts of up to about 3eV, the theoretical cross-sections are in good agreement with each other and with the experimental results. In addition, the complex de-excitation cascades after the creation of inner-shell holes in the Fe+ ion were tracked on the atomic fine-structure level. The corresponding theoretical results for the product charge-state distributions are in much better agreement with the experimental data than previously published configuration-average results. The present experimental and theoretical results are valuable for opacity calculations and are expected to pave the way to a more accurate determination of the iron abundance in the interstellar medium.2017ApJ...849....5Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/849/5CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+AS/97/443 : Fluorescence for Be to Zn (Kaastra+ 1993)J/A+AS/109/125 : Photoionisation cross section (Verner+, 1995)J/ApJ/700/1299 : Gas-phase element depletions in the ISM (Jenkins, 2009)J/ApJ/808/174 : FeII radiative transition rates (Bautista+, 2015)J/ApJ/813/16 : Fe^7+^ ionization cross section (Hahn+, 2015)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/849/5https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/849/5http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/849/5https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/849/5https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/849/5http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/849/5GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/ApJ/849/5/table2Measured cross sectionsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintE[680.9/921.1] Photon energyeVphys.energy;phys.atmol.levelfloatsig1[0.008/2.6] Cross section for 1-fold photoionization of Fe+ ionsMbarnmeta.id.cross;phys.atmol.crossSectiondoublee_sig1[0.003/0.02] Statistical experimental uncertainty in sig1 (1)Mbarnstat.errordoublesig2[0.1/3.3] Cross section for 2-fold photoionization of Fe+ ionsMbarnmeta.id.cross;phys.atmol.crossSectiondoublee_sig2[0.001/0.02] Statistical experimental uncertainty in sig2 (1)Mbarnstat.errordoublesig3[0.03/4.7] Cross section for 3-fold photoionization of Fe+ ionsMbarnmeta.id.cross;phys.atmol.crossSectiondoublee_sig3[0.001/0.02] Statistical experimental uncertainty in sig3 (1)Mbarnstat.errordoublesig4[0/0.6]? Cross section for 4-fold photoionization of Fe+ ionsMbarnmeta.id.cross;phys.atmol.crossSectiondoublenullablee_sig4[0/0.008]? Statistical experimental uncertainty in sig4 (1)Mbarnstat.errordoublenullablesig5[0/0.1]? Cross section for 5-fold photoionization of Fe+ ionsMbarnmeta.id.cross;phys.atmol.crossSectiondoublenullablee_sig5[0/0.003]? Statistical experimental uncertainty in sig5 (1)Mbarnstat.errordoublenullablesig6[-3.3e-05/0.006] Cross section for 6-fold photoionization of Fe+ ionsMbarnmeta.id.cross;phys.atmol.crossSectiondoublee_sig6[1.4e-05/0.0004] Statistical experimental uncertainty in sig6 (1)Mbarnstat.errordoublesigT[0/11]? Total cross section for m-fold photoionization of Fe+ ionsMbarnmeta.id.cross;phys.atmol.crossSectiondoublenullablee_sigT[0/0.03]? Statistical experimental uncertainty in sigT (1)Mbarnstat.errordoublenullableq[0/4.3]? Mean product charge-state, Eq. 2, Fig. 8bphys.atmol.ionStagedoublenullablee_q[0/0.03]? Statistical experimental uncertainty in qstat.errordoublenullable