J/ApJ/780/76ivo://CDS.VizieR/J/ApJ/780/76doi:10.26093/cds/vizier.17800076CDSKisielius R.Kulkarni V.P.Ferland G.J.Bogdanovich P.Lykins M.L.2018-01-30T07:18:24Z2015-07-09T13:35:35ZCDS support team

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

cds-question@unistra.fratomic-physicsAbsorption-line spectroscopy is a powerful tool used to estimate element abundances in both the nearby and distant universe. The accuracy of the abundances thus derived is naturally limited by the accuracy of the atomic data assumed for the spectral lines. We have recently started a project to perform new extensive atomic data calculations used for optical/UV spectral lines in the plasma modeling code Cloudy using state of the art quantal calculations. Here, we demonstrate our approach by focussing on S II, an ion used to estimate metallicities for Milky Way interstellar clouds as well as distant damped Lyman-alpha (DLA) and sub-DLA absorber galaxies detected in the spectra of quasars and gamma-ray bursts. We report new extensive calculations of a large number of energy levels of S II, and the line strengths of the resulting radiative transitions. Our calculations are based on the configuration interaction approach within a numerical Hartree-Fock framework, and utilize both non-relativistic and quasirelativistic one-electron radial orbitals. The results of these new atomic calculations are then incorporated into Cloudy and applied to a lab plasma, and a typical DLA, for illustrative purposes. The new results imply relatively modest changes ({approx}0.04dex) to the metallicities estimated from SII in past studies. These results will be readily applicable to other studies of SII in the Milky Way and other galaxies.2014ApJ...780...76Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/780/76CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJS/188/32 : Breit-Pauli transition probabilities for SII (Tayal+, 2010)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/780/76https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/780/76http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/780/76https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/780/76https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/780/76http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/780/76GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/ApJ/780/76/table1Comparison of calculated SII energy levels with experimental datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMSDIndicates that the data provided at the bottom of the table are the Mean-Square Deviation (MSD) valuesmeta.codecharIndex[1/49]? Level indexmeta.idintnullableStateConfigurationphys.atmol.configurationJ[0.5/4.5]? The J valuephys.atmol.qnfloatnullableE1[0/154834] Our SII energy level value obtained in the CI_HF+TRO_ approximation (1)cm**-1stat.value;phys.atmol.levelintE2[0/155791] Our SII energy level value obtained in the CI_QR+TRO_ approximation (2)cm**-1stat.value;phys.atmol.levelintExp[0/151652]? Experimental value of SII energy levelcm**-1stat.value;phys.atmol.levelintnullableE3[0/153365] SII energy level value calculated by Froese Fischer et al. (2006ADNDT..92..607F) with a MultiConfiguration Hartree-Fock (MCHF) method (3)cm**-1stat.value;phys.atmol.levelintE4[0/151745] SII energy level value of SII computed by Tayal & Zatsarinny 2010 (cat. J/ApJS/188/32) with a MultiConfiguration Hartree-Fock (MCHF) method with Term-Dependant (TD) non-orthogonal orbital (4)cm**-1stat.value;phys.atmol.levelintJ/ApJ/780/76/table3Transition line strengths S (in a.u.) for SII determined in the CI_HF+TRO_ approximationrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintData[S] Transition data type (S=line strength S)meta.notecharTypeTransition line type (E1, E2, E3, or M1)meta.notecharIlow[1/44] Lower level indexmeta.idintIup[2/49] Upper level indexmeta.idint