J/ApJ/753/13ivo://CDS.VizieR/J/ApJ/753/13doi:10.26093/cds/vizier.17530013CDSMathew B.Banerjee D.P.K.Subramaniam A.Ashok N.M.2017-10-12T13:00:19Z2016-01-11T13:21:05ZCDS support team

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

cds-question@unistra.frline-intensitiesbe-starsspectroscopystellar-spectral-typesThe possibility of the Ly{beta} fluorescence mechanism being operational in classical Be (CBe) stars and thereby contributing to the strength of the OI{lambda}8446 line has been recognized for long. However, this supposition needs to be quantified by comparing observed and predicted OI line ratios. In the present work, optical and near-infrared spectra of CBe stars are presented. We analyze the observed strengths of the OI{lambda}7774, {lambda}8446, {lambda}11287, and {lambda}13165 lines, which have been theoretically proposed as diagnostics for identifying the excitation mechanism. We have considered and examined the effects of Ly{beta} fluorescence, collisional excitation, recombination, and continuum fluorescence on these O I line strengths. From our analysis it appears that the Ly{beta} fluorescence process is indeed operative in Be stars.2012ApJ...753...13Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/753/13CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/other/BASI/39.517 : Spectroscopy of classical Be stars (Mathew+, 2011)J/ApJ/700/1216 : Spectroscopy of Be stars in open clusters (McSwain+, 2009)J/A+A/451/1053 : Fundamental parameters of Be stars (Fremat+, 2006)J/ApJ/653/657 : Spectroscopic obs. of Herbig Ae/Be stars (Manoj+, 2006)J/AJ/129/856 : Herbig Ae/Be stars in nearby OB assoc. (Hernandez+, 2005)J/MNRAS/358/66 : uvby{beta} photometry of NGC 663 (Fabregat+, 2005)J/ApJS/161/118 : byH{alpha} photometry in open clusters (McSwain+, 2005)J/A+A/384/473 : O, B and Be stars equivalent widths (Lenorzer+, 2002)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/753/13https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/753/13http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/753/13https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/753/13https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/753/13http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/753/13GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/753/13/table1 (List of classical Be stars which show OI(7774) and OI(8446) in emission, with equivalent width and line flux ratio estimates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/753/13/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/753/13/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/753/13/table1?GETtext/xml+votable180.050000true305.08512538.62686110.0055555555555555566/1287 2940 2942 3170 3254 3256 3257 3621 3622 3632 14263 14306 14310 14314 14415 14419 14622 14643 14644 14646 14719 15376 15443 15622 15632 21517 21633 22197 29523 40610https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/753/13?format=asciiOpticaldefaultJ/ApJ/753/13/table1List of classical Be stars which show OI(7774) and OI(8446) in emission, with equivalent width and line flux ratio estimatesClusterCluster namemeta.id.parentcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar designation within the cluster, as in Mathew & Subramaniam 2011 (J/other/BASI/39.517)meta.id;meta.maincharSpTMK spectral typesrc.spTypecharDateObservation datetime.epoch;obsnullableW7774OI(7774) observed equivalent width in {AA}0.1nmspect.line.eqWidthfloatW8446OI(8446) observed equivalent width in {AA}0.1nmspect.line.eqWidthfloatW7774cOI(7774) equivalent width, corrected for underlying stellar absorption component0.1nmspect.line.eqWidthfloatW8446cOI(8446) equivalent width, corrected for underlying stellar absorption component0.1nmspect.line.eqWidthfloatIrat[0.7/10.6] Line flux ratio I(8446/7774)spect.line.intensity;arith.ratiofloatE(B-V)[0.1/2] Extinction E(B-V)magphot.color.excessfloatIc[0.4/6.6] Extinction-corrected line flux ratio of I(8446/7774)spect.line.intensity;arith.ratiofloatSimbadSimbad column added by the CDSmeta.ref.urlchar_RAPosition from Mathew et al., 2001, Cat. J/other/BASI/39.517 (right ascension part)degpos.eq.ra;meta.main_DEPosition from Mathew et al., 2001, Cat. J/other/BASI/39.517 (declination part)degpos.eq.dec;meta.main