J/A+A/657/A121ivo://CDS.VizieR/J/A+A/657/A121doi:10.26093/cds/vizier.36570121CDSAllard N.F.Spiegelman F.Kielkopf J.F.Bourdreux S.2022-05-18T14:30:50Z2022-01-20T07:00:15ZCDS support team

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

cds-question@unistra.fratomic-physicsIn order to investigate the near wing of the Lyman-{alpha} line, accurate line profile calculations and molecular data are both required due to the existence of a close line satellite responsible for its asymmetrical shape. Lyman-{alpha} lines observed with the Cosmic Origin Spectograph (COS) on the Hubble Space Telescope (HST) show this peculiarity in the spectra of DBA and DA white dwarf stars. A similar asymmetrical shape in the blue wing can be predicted in the Balmer-{alpha} line of H perturbed by He and H atoms. In continuation with a very recent work on the Lyman-{alpha} line, where the n = 2 potential energies and transition dipole moments from the ground state were determined, we present new accurate H-He potential energies and electronic transition dipole moments involving the molecular states correlated with H(n=3)+He and their transition dipole moments with the states correlated with H(n=2)+He. Those new data and existing molecular data for H(n=2,3)-H are used to provide a theoretical investigation of the collisional effects in the blue wing of the Balmer-{alpha} line of H perturbed by He and H atoms. We note the consequences for the Balmer-{alpha} line shape in the physical conditions found in the cool atmosphere of DZA white dwarfs where helium densities may be as high as 10^21^cm^-3^. This study is undertaken with a unified theory of spectral line broadening valid at very high helium densities.2022A&A...657A.121Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/657/A121CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/657/A121https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/657/A121http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/657/A121https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/657/A121https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/657/A121http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/657/A121GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/657/A121/fig6Unified profile of the Balmer alpha line broadened by He collisions with the He density 5x10^-20^cm^-3^. The temperature is 8000K.recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDeltaomegaWavenumber (energy) offset from the line centercm**-1phys.energy;phys.atmol.transitionintsigmaComputed cross section1e-16cm**2meta.id.cross;phys.atmol.crossSection;meta.modelleddoubleJ/A+A/657/A121/fig10Unified profile of the Balmer alpha line resonance broadened by H-H collisions with the H density 10^-18^cm^3^. The temperature is 5000K.DeltaomegaWavenumber (energy) offset from the line centercm**-1phys.energy;phys.atmol.transitionintsigmaComputed cross section1e-20cm**2meta.id.cross;phys.atmol.crossSection;meta.modelleddoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint