J/A+AS/132/173ivo://CDS.VizieR/J/A+AS/132/173CDSLi J.Z.Hu J.Y.1998-11-07T17:35:32Z1998-11-07T18:35:10ZCDS support team

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

cds-question@unistra.frpre-main-sequence-starsx-ray-sourcesWe present results of an extensive search for weak-line T Tauri stars (WTTS) in the outskirts of the Taurus-Auriga molecular cloud on the basis of the ROSAT All-Sky Survey Bright Source Catalog (Cat. <IX/10>). Our surveyed region extends from 2h 40m to 5h 40m in right ascension and from 10deg to 40deg in declination, with the central part of Taurus-Auriga(4h<{alpha}<5h, 15deg<{delta}<34deg), accomplished by Wichmann et al. (1996, Cat. <J/A+A/312/439>), excluded. Within a sky coverage of about 10$^{3}$ square degrees, 219 X-ray sources fullfill the criteria for selecting program sources suggested by Neuhauser et al. (1995A&A...295L...5N) and 164 of these X-ray sources were found to have at least one optical counterpart with E magnitude brighter than 16. Low-resolution spectroscopic observation has been carried out in order to discard early type stars and galaxies from the sample, additional intermediate-resolution spectra of a sub-sample of 156 late type optical counterparts were obtained for spectral classification and for the calculation of the equivalent width of H{alpha} emission and LiI line absorption at 6707{AA}. Excluding 2 previously identified WTTS, a total of 75 new candidate WTTS and one possible classical T Tauri star have been discovered in our study. The majority of the newly found Li-rich optical counterparts are believed to b e PMS stars rather than ZAMS stars as those of the Pleiades.1998A&AS..132..173Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+AS/132/173CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1996)J/A+A/312/439 : New T Tauri stars in Taurus-Auriga (Wichmann+, 1996)J/A+A/297/391 : T Tauri stars ROSAT survey (Neuhaeuser+, 1995)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+AS/132/173https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+AS/132/173http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+AS/132/173https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+AS/132/173https://vizier.iucaa.in/viz-bin/votable?-source=J/A+AS/132/173http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+AS/132/173GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+AS/132/173/table2 (Optical data of the newly discovered candidate WTTS)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+AS/132/173/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+AS/132/173/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+AS/132/173/table2?GETtext/xml+votable180.050000true40.1237520.1006940.005555555555555556Cone search capability for table J/A+AS/132/173/table3 (Optical data of the possible CTTS discovered and the two previously found WTTS candidates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+AS/132/173/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/A+AS/132/173/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+AS/132/173/table3?GETtext/xml+votable180.050000true82.28511.8686110.005555555555555556Cone search capability for table J/A+AS/132/173/table4 (Optical data of the probable cloud members of Taurus-Aurigae)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+AS/132/173/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/A+AS/132/173/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+AS/132/173/table4?GETtext/xml+votable180.050000true41.3512514.5884720.005555555555555556Cone search capability for table J/A+AS/132/173/table5 (Optical data of the possible optical counterparts to the RASS sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+AS/132/173/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/A+AS/132/173/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+AS/132/173/table5?GETtext/xml+votable180.050000true40.88791717.1419440.005555555555555556https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+AS/132/173?format=asciiX-raydefaultJ/A+AS/132/173/table2Optical data of the newly discovered candidate WTTSNoNumbermeta.idintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintm_No[s] Multiplicity index on Nometa.code.multipchar1RXSRASS (Cat. <IX/10>) designationmeta.id;meta.maincharRA2000Right Ascension for equinox 2000.0pos.eq.ra;meta.mainDE2000Declination for equinox 2000.0pos.eq.dec;meta.mainVmag? Visual magnitude of the optical counterpartmagphot.mag;em.opt.Vfloatnullablen_Vmag[V?] ? for unknown valuemeta.notecharEW(Ha)? Equivalent width for H{alpha} (1)0.1nmspect.line.eqWidthfloatnullableEW(LiI)? Equivalent width for LiI absorption line (1)0.1nmspect.line.eqWidthfloatnullableSpTypeSpectral type (2)src.spTypecharNameCatalog identifiermeta.idcharComcomments on optical positionmeta.notecharJ/A+AS/132/173/table3Optical data of the possible CTTS discovered and the two previously found WTTS candidatesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNoNumbermeta.idintm_No[s] Multiplicity index on Nometa.code.multipchar1RXSRASS (Cat. <IX/10>) designationmeta.id;meta.maincharRA2000Right Ascension for equinox 2000.0pos.eq.ra;meta.mainDE2000Declination for equinox 2000.0pos.eq.dec;meta.mainVmag? Visual magnitude of the optical counterpartmagphot.mag;em.opt.Vfloatnullablen_Vmag[V?] ? for unknown valuemeta.notecharEW(Ha)? Equivalent width for H{alpha} (1)0.1nmspect.line.eqWidthfloatnullableEW(LiI)? Equivalent width for LiI absorption line (1)0.1nmspect.line.eqWidthfloatnullableSpTypeSpectral type (2)src.spTypecharNameCatalog identifiermeta.idcharComcomments on optical positionmeta.notecharJ/A+AS/132/173/table4Optical data of the probable cloud members of Taurus-AurigaeNoNumbermeta.idintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintm_No[s] Multiplicity index on Nometa.code.multipchar1RXSRASS (Cat. <IX/10>) designationmeta.id;meta.maincharRA2000Right Ascension for equinox 2000.0pos.eq.ra;meta.mainDE2000Declination for equinox 2000.0pos.eq.dec;meta.mainVmag? Visual magnitude of the optical counterpartmagphot.mag;em.opt.Vfloatnullablen_Vmag[V?] ? for unknown valuemeta.notecharEW(Ha)? Equivalent width for H{alpha} (1)0.1nmspect.line.eqWidthfloatnullableEW(LiI)? Equivalent width for LiI absorption line (1)0.1nmspect.line.eqWidthfloatnullableSpTypeSpectral type (2)src.spTypecharNameCatalog identifiermeta.idcharComcomments on optical positionmeta.notecharJ/A+AS/132/173/table5Optical data of the possible optical counterparts to the RASS sourcesSpTypeSpectral type (2)src.spTypecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNoNumbermeta.idintm_No[s] Multiplicity index on Nometa.code.multipchar1RXSRASS (Cat. <IX/10>) designationmeta.id;meta.maincharRA2000Right Ascension for equinox 2000.0pos.eq.ra;meta.mainDE2000Declination for equinox 2000.0pos.eq.dec;meta.mainVmag? Visual magnitude of the optical counterpartmagphot.mag;em.opt.Vfloatnullablen_Vmag[V?] ? for unknown valuemeta.notecharEW(Ha)? Equivalent width for H{alpha} (1)0.1nmspect.line.eqWidthfloatnullableEW(LiI)? Equivalent width for LiI absorption line (1)0.1nmspect.line.eqWidthfloatnullableNameCatalog identifiermeta.idcharComcomments on optical positionmeta.notechar